Air at the Zenica - Centar station

Zenica, Zenica-Doboj Canton · Federation of Bosnia and Herzegovina

Network: Federal Hydrometeorological Institute · Station code: BA0037A

This year, up to yesterday (October 6)

at least

10 days

with a daily average of sulphur dioxide (SO₂) above the legal limit of 125 µg/m³.

3 days are allowed in the whole year.

at least 7 days more than allowed

In 2025: 40 days above the limit, 3 allowed.

at least

32 days

with an 8-hour average of ozone (O₃) above the target value of 120 µg/m³.

The target value allows 25 such days a year, averaged over three years.

Worst day: January 22, 2026, SO₂ 288 µg/m³ as a daily average, 2.3 times the limit.

Also: at least 34 days above the legal daily limit for PM10 of 50 µg/m³ (too few readings to compare with the allowed number).

Also: at least 18 hours above the legal hourly limit for SO₂ of 350 µg/m³ (too few readings to compare with the allowed number).

Daily average for 212 of 279 days · data for 2026 not yet finally verified · Yardstick: legal limits in the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19, 3/21)

All figures by year and month

Poor

Air now · Measured at 21:00

Latest values

Latest value: 21:00

Readings
Pollutant	Value	Level
PM10	66.6 µg/m³	Moderate
NO₂	89.3 µg/m³	Poor
O₃	18.5 µg/m³	Good
SO₂	42.5 µg/m³	Moderate

How the air is changing

Over the last seven days there was more PM10, NO₂, and SO₂ in the air than the week before.

PM10: average 37.2 µg/m³, week before 19.3 µg/m³
NO₂: average 32.5 µg/m³, week before 21.7 µg/m³
O₃: average 54.1 µg/m³, week before 49.9 µg/m³
SO₂: average 43.4 µg/m³, week before 37.7 µg/m³

There are not enough readings to compare with the month before.

PM10: too few readings to compare
NO₂: too few readings to compare
O₃: too few readings to compare
SO₂: too few readings to compare

Show

Particulate matter PM10

66.6

Nowµg/m³

Measured at 21:00

53.4

Last 24 hoursµg/m³

measured in 92 % of hours · provisional

37.2

Last 7 daysµg/m³

measured in 99 % of hours · provisional

too few readings

Last 30 days

measured in 49 % of hours · provisional

too few readings

Last 12 months

measured in 78 % of hours · 1 month with too few readings · provisional

Days in 2023: PM10, daily average above 50 µg/m³

63 days above the limit.

above the limit
below the limit
too few readings for the day
no PM10 data in the EEA database

Days above the limit with values (63)

Jan 5 57
Jan 6 66
Jan 7 61
Jan 8 68
Jan 12 66
Jan 14 62
Jan 16 80
Jan 23 66
Jan 24 61
Jan 31 72
Feb 1 71
Feb 2 66
Feb 9 60
Feb 10 90
Feb 11 101
Feb 12 129
Feb 13 98
Feb 14 85
Feb 15 81
Feb 16 97
Feb 17 79
Feb 20 57
Feb 21 66
Feb 22 64
Feb 23 69
Feb 24 58
Feb 25 54
Mar 1 55
Mar 2 72
Mar 3 91
Mar 4 73
Mar 5 78
Mar 6 61
Mar 23 52
Jun 23 60
Aug 18 58
Nov 10 69
Nov 13 54
Nov 20 71
Nov 21 76
Nov 27 50
Nov 28 91
Dec 5 79
Dec 8 57
Dec 9 86
Dec 10 113
Dec 11 63
Dec 12 69
Dec 13 75
Dec 17 57
Dec 18 80
Dec 19 87
Dec 20 87
Dec 21 120
Dec 22 50
Dec 23 67
Dec 24 72
Dec 25 52
Dec 26 54
Dec 27 77
Dec 29 85
Dec 30 85
Dec 31 76

Values in µg/m³, limit 50 µg/m³.

Months of 2023

Month	Days above 50	Average	Highest day
January	10 above the number allowed	45	80
February	17 above the number allowed	60	129
March	7 above the number allowed	44	91
April	0	30	42
May	0	28	49
June	1 above the number allowed	23	60
July	0	31	48
August	1 above the number allowed	29	58
September	0	28	38
October	0	31	46
November	6 above the number allowed	35	91
December	21 above the number allowed	60	120

Values in µg/m³. ■ marks a month with at least one day above the limit; the number allowed applies to the whole year. “No readings”: days on which not a single reading came from the station.

measuredmodel estimate, not countedday above the limit (daily average)

Not shown: 1 unverified hour with an implausible value (see the note under the yearly table).

Last 7 days, every hour: PM10 in µg/m³

Values as a table

Hour to	µg/m³	Note
Wednesday, 10/7
22:00	45	model estimate, not counted
21:00	66.6
20:00	56.3
19:00	36.8
18:00	24.6
17:00	29.5
16:00	32.7
15:00	41.7
14:00	60.4
13:00	57.9
12:00	51.6
11:00	67
10:00	66.4
09:00	51.6
08:00	51.6
07:00	49.7
06:00	50.4
05:00	50.7
04:00	51.2
03:00	49.5
02:00	58.8
01:00	77.9
Tuesday, 10/6
00:00	91.4
23:00	88.5
22:00	86.7
21:00	84.8
20:00	74.2
19:00	65.6
18:00	64.5
17:00	67.2
16:00	83.7
15:00	136.9
14:00	111.1
13:00	72.8
12:00	47.2
11:00	53.7
10:00	55
09:00	49.6
08:00	37.7
07:00	37.7
06:00	36.8
05:00	37.4
04:00	45.3
03:00	49.8
02:00	62.5
01:00	83.2
Monday, 10/5
00:00	76.3
23:00	54.7
22:00	53.9
21:00	55.6
20:00	53.5
19:00	43.2
18:00	31.6
17:00	21.2
16:00	29.4
15:00	30.6
14:00	27.1
13:00	25.6
12:00	30
11:00	34.2
10:00	36.3
09:00	32.4
08:00	31.3
07:00	29.3
06:00	28.4
05:00	29.1
04:00	32.5
03:00	336.2
01:00	51.9
Sunday, 10/4
00:00	59.7
23:00	60.9
22:00	54.3
21:00	46.5
20:00	35.9
19:00	24.7
18:00	18.1
17:00	10.2
16:00	9.1
15:00	14
14:00	18.4
13:00	17.7
12:00	21.5
11:00	28
10:00	24.3
09:00	20.3
08:00	22.6
07:00	21.8
06:00	24.1
05:00	23.8
04:00	23.9
03:00	27.5
02:00	34.8
01:00	46.7
Saturday, 10/3
00:00	46.8
23:00	47.2
22:00	38.5
21:00	34.1
20:00	23.4
19:00	18
18:00	14.1
17:00	13.3
16:00	16.6
15:00	16.2
14:00	17.1
13:00	19.8
12:00	21
11:00	28.1
10:00	29.9
09:00	24.6
08:00	24.3
07:00	22.5
06:00	22.1
05:00	22.8
04:00	26.9
03:00	30.5
02:00	40.4
01:00	71.6
Friday, 10/2
00:00	59.3
23:00	131.9
22:00	239.5
21:00	44.6
20:00	29.2
19:00	22.1
18:00	11.2
17:00	12.8
16:00	14.6
15:00	20.6
14:00	20.7
13:00	15.1
12:00	22.4
11:00	26.8
10:00	26.6
09:00	25
08:00	19.3
07:00	16.5
06:00	18.1
05:00	15.7
04:00	14.8
03:00	19
02:00	26.1
01:00	29.6
Thursday, 10/1
00:00	38
23:00	40.2
22:00	34.5
21:00	27.6
20:00	15.9
19:00	12.3
18:00	13.6
17:00	18.5
16:00	19.6
15:00	15.2
14:00	12
13:00	15.5
12:00	17.5
11:00	25.5
10:00	30.8
09:00	26.5
08:00	23.7
07:00	18.6
06:00	19
05:00	17
04:00	19.4
03:00	26.4
02:00	30.8
01:00	31.4

day above the limittoo few readingslegal daily limit, 50 µg/m³no data from the station

Last 30 days, daily average: PM10 in µg/m³ · 2 days above the limit

Values as a table

Day	µg/m³	Note
Tue, 10/6	67.6	above the limit · provisional
Mon, 10/5	51.1	above the limit · provisional
Sun, 10/4	28.7	provisional
Sat, 10/3	27.9	provisional
Fri, 10/2	36.7	provisional
Thu, 10/1	22.9	provisional
Wed, 9/30	25.7	provisional
Tue, 9/29	29.7	provisional
Mon, 9/28	27.5	provisional
Sun, 9/27	24.9	provisional
Sat, 9/26	19.1	provisional
Fri, 9/25	7.8	provisional
Thu, 9/24	15.5	provisional
Wed, 9/23	10.4	provisional
Tue, 9/22		too few readings
Mon, 9/21		no data from the station
Sun, 9/20		no data from the station
Sat, 9/19		no data from the station
Fri, 9/18		no data from the station
Thu, 9/17		no data from the station
Wed, 9/16		no data from the station
Tue, 9/15		no data from the station
Mon, 9/14		no data from the station
Sun, 9/13		no data from the station
Sat, 9/12		no data from the station
Fri, 9/11		no data from the station
Thu, 9/10		no data from the station
Wed, 9/9		no data from the station
Tue, 9/8		no data from the station
Mon, 9/7		no data from the station

Last 12 monthsthis month so fara year earlierlegal annual limit, 40 µg/m³month with days without data from the station

Last 12 months, monthly average: PM10 in µg/m³

Values as a table

Month	µg/m³	a year earlier	Note
October 2026 so far	39.1	17	measured in 99 % of hours · provisional · year before: same days
September 2026	too few readings	20.2	measured in 30 % of hours · provisional · 20 days without data from the station
August 2026	42.8	22.7	measured in 85 % of hours · provisional
July 2026	too few readings	20.9	measured in 72 % of hours · provisional · 6 days without data from the station
June 2026	18.3	25.8	measured in 86 % of hours · provisional · 1 day without data from the station
May 2026	14.5	16	measured in 94 % of hours · provisional · 1 day without data from the station
April 2026	22.4	21.6	measured in 79 % of hours · provisional · 4 days without data from the station
March 2026	too few readings	30.7	measured in 71 % of hours · provisional · 7 days without data from the station
February 2026	35.8	56.9	measured in 81 % of hours · provisional · 5 days without data from the station
January 2026	65.1	60.1	measured in 88 % of hours · provisional · 2 days without data from the station
December 2025	48.4	37.5	measured in 93 % of hours · verified
November 2025	44.6	45.7	measured in 83 % of hours · verified · 4 days without data from the station

PM10 by year

Yardstick: legal limits in the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19, 3/21)

Measure	2026*	2025	2024	2023
Days above 50 µg/m³ (allowed 35)	≥ 34²	56 above the number allowed	54 above the number allowed	63 above the number allowed
Days above 150 µg/m³ (warning threshold FBiH)	0	1 above the number allowed	0	0
Days above 300 µg/m³ (alert threshold FBiH)	0	0	0	0
Annual average, µg/m³ (legal limit 40)	too few	32.8	31.6	36.7
Highest daily average, µg/m³	148January 23	158January 22	131January 23	129February 12
Highest hourly value, µg/m³	521August 31	350November 26	305March 27	328January 4
Hours measured	77 %	92 %	95 %	96 %
Days without any reading from the station	46	7	2	0

* 2026 up to October 6; the average since the start of the year is not yet an annual average.

The monitoring networks have not yet finally verified this year’s data. The EEA publishes verified values once a year.

≥ means at least: more than a tenth of the days or hours are missing, so the real number may be higher.

² Too few readings to compare with the number allowed: the figure covers only what was measured.

Unverified hourly values of particulate matter from 975 µg/m³ up, and single spikes from 500 µg/m³ up between low values, count as missing. In the verified data for BiH from 2023 to 2025 no hour was above 600 µg/m³.

■ and a figure in red: more than is allowed for the whole year.

There is no allowed number for the warning and alert thresholds: every such hour or day is in red.

The column for 2023 is shown on wider screens.

Compared with the new EU rules and the WHO recommendation

This is not the yardstick for the verdict above, only a comparison. From 2030 the EU tightens its limits (Directive (EU) 2024/2881), and since 2021 the World Health Organization has recommended even lower values.

EU from 2030: daily 45 µg/m³, 18 days allowed. In 2023 there were 75 such days.
WHO 2021: daily 45 µg/m³, at most three to four days a year. In 2023 there were 75 such days.
EU from 2030: annual average 20 µg/m³. Average in 2023: 37 µg/m³.
WHO 2021: annual average 15 µg/m³. Average in 2023: 37 µg/m³.

Sources: Directive (EU) 2024/2881, Annex I; WHO global air quality guidelines 2021, table 0.1. Checked against the texts on 7 October 2026.

The worst days of 2023

Day	Average	Times the limit
Feb 12, 2023	129	2.6 ×
Dec 21, 2023	120	2.4 ×
Dec 10, 2023	113	2.3 ×
Feb 11, 2023	101	2.0 ×
Feb 13, 2023	98	2.0 ×

Daily average in µg/m³, daily limit 50 µg/m³. Days with the same unverified value over many hours are not on this list.

Nitrogen dioxide NO₂

89.3

Nowµg/m³

Measured at 21:00

35.8

Last 24 hoursµg/m³

measured in 92 % of hours · provisional

32.5

Last 7 daysµg/m³

measured in 100 % of hours · provisional

too few readings

Last 30 days

measured in 49 % of hours · provisional

too few readings

Last 12 months

measured in 74 % of hours · provisional

Days in 2023: NO₂, daily average above 85 µg/m³

No measured day above the limit.

above the limit
below the limit
too few readings for the day
no NO₂ data in the EEA database

Months of 2023

Month	Days above 85	Hours above 200	Average	Highest day
January	0	0	23	39
February	0	0	27	48
March	0	0	23	38
April	0	0	15	28
May	0	0	17	23
June	0	0	14	19
July	0	0	15	22
August	0	0	16	20
September	0	0	16	25
October	0	0	too few	10
November
December	0	0	too few

Values in µg/m³. ■ marks a month with at least one day above the limit; the number allowed applies to the whole year. “No readings”: days on which not a single reading came from the station.

measuredmodel estimate, not countedlegal hourly limit, 200 µg/m³

Last 7 days, every hour: NO₂ in µg/m³

Values as a table

Hour to	µg/m³	Note
Wednesday, 10/7
22:00	28	model estimate, not counted
21:00	89.3
20:00	74.4
19:00	57
18:00	35.7
17:00	22.9
16:00	23.8
15:00	22.2
14:00	26
13:00	29.8
12:00	36.6
11:00	38.7
10:00	43.3
09:00	42.2
08:00	35.6
07:00	25.2
06:00	16.4
05:00	17.2
04:00	21.4
03:00	24
02:00	24.8
01:00	33.1
Tuesday, 10/6
00:00	47.6
23:00	68.6
22:00	90.4
21:00	96.9
20:00	86.7
19:00	73.4
18:00	56.4
17:00	30.1
16:00	26.6
15:00	30.6
14:00	39.6
13:00	22.3
12:00	26.4
11:00	33.1
10:00	38.7
09:00	38.2
08:00	35.8
07:00	25.2
06:00	16.6
05:00	19.6
04:00	24.2
03:00	31.1
02:00	44.8
01:00	51.4
Monday, 10/5
00:00	57.7
23:00	60.3
22:00	71.8
21:00	88.7
20:00	74.3
19:00	49.4
18:00	32.4
17:00	30.4
16:00	23.2
15:00	23
14:00	23.6
13:00	20.8
12:00	24.7
11:00	28
10:00	33.6
09:00	37.5
08:00	32.3
07:00	24.1
06:00	16.4
05:00	15.1
04:00	19.6
03:00	22.3
02:00	20.8
01:00	31.3
Sunday, 10/4
00:00	48.6
23:00	67.7
22:00	85.8
21:00	86.8
20:00	74.1
19:00	34.6
18:00	14.8
17:00	11.7
16:00	10.8
15:00	10.9
14:00	14.1
13:00	14.5
12:00	14.9
11:00	22.2
10:00	18.7
09:00	18.6
08:00	15.5
07:00	14.4
06:00	12.1
05:00	12.4
04:00	17.3
03:00	21.8
02:00	26
01:00	36.9
Saturday, 10/3
00:00	52.9
23:00	67.2
22:00	80.2
21:00	80
20:00	65.8
19:00	32
18:00	12.7
17:00	8.4
16:00	10
15:00	12.6
14:00	18.7
13:00	17.6
12:00	23.2
11:00	20.9
10:00	26.8
09:00	27.5
08:00	25.5
07:00	17.8
06:00	14.1
05:00	16.8
04:00	23.9
03:00	35.1
02:00	46.7
01:00	46.5
Friday, 10/2
00:00	51.9
23:00	56.4
22:00	77.5
21:00	88.8
20:00	80.1
19:00	33.5
18:00	15.5
17:00	12.5
16:00	14.2
15:00	21.3
14:00	17.4
13:00	21.7
12:00	25.9
11:00	28.5
10:00	35.1
09:00	29.5
08:00	27.8
07:00	21.3
06:00	12.9
05:00	14.5
04:00	15.8
03:00	20.5
02:00	23.6
01:00	31.1
Thursday, 10/1
00:00	39.5
23:00	60.7
22:00	70.6
21:00	72.6
20:00	57
19:00	20.4
18:00	9.7
17:00	10.9
16:00	10.5
15:00	13.3
14:00	12.3
13:00	10.5
12:00	12
11:00	24.9
10:00	25.6
09:00	24.2
08:00	22.8
07:00	18.4
06:00	10.3
05:00	12.7
04:00	16.4
03:00	17.5
02:00	23.6
01:00	32.3

too few readingslegal daily limit, 85 µg/m³no data from the station

Last 30 days, daily average: NO₂ in µg/m³

Values as a table

Day	µg/m³	Note
Tue, 10/6	43.9	provisional
Mon, 10/5	35.9	provisional
Sun, 10/4	29.4	provisional
Sat, 10/3	32.6	provisional
Fri, 10/2	32.4	provisional
Thu, 10/1	26.2	provisional
Wed, 9/30	26.9	provisional
Tue, 9/29	27.3	provisional
Mon, 9/28	27.5	provisional
Sun, 9/27	19.6	provisional
Sat, 9/26	21.6	provisional
Fri, 9/25	15.9	provisional
Thu, 9/24	22.5	provisional
Wed, 9/23	17.8	provisional
Tue, 9/22		too few readings
Mon, 9/21		no data from the station
Sun, 9/20		no data from the station
Sat, 9/19		no data from the station
Fri, 9/18		no data from the station
Thu, 9/17		no data from the station
Wed, 9/16		no data from the station
Tue, 9/15		no data from the station
Mon, 9/14		no data from the station
Sun, 9/13		no data from the station
Sat, 9/12		no data from the station
Fri, 9/11		no data from the station
Thu, 9/10		no data from the station
Wed, 9/9		no data from the station
Tue, 9/8		no data from the station
Mon, 9/7		no data from the station

Last 12 monthsthis month so fara year earlierlegal annual limit, 40 µg/m³month with days without data from the station

Last 12 months, monthly average: NO₂ in µg/m³

Values as a table

Month	µg/m³	a year earlier	Note
October 2026 so far	33.4	8.3	measured in 100 % of hours · provisional · year before: same days
September 2026	too few readings	18.5	measured in 30 % of hours · provisional · 20 days without data from the station
August 2026	21.8	22.8	measured in 97 % of hours · provisional
July 2026	too few readings	19.7	measured in 74 % of hours · provisional · 6 days without data from the station
June 2026	13.8	20.1	measured in 93 % of hours · provisional · 1 day without data from the station
May 2026	17	19.2	measured in 94 % of hours · provisional · 1 day without data from the station
April 2026	20.7	23.8	measured in 79 % of hours · provisional · 4 days without data from the station
March 2026	30.1	30.3	measured in 75 % of hours · provisional · 7 days without data from the station
February 2026	27.7	41.9	measured in 81 % of hours · provisional · 5 days without data from the station
January 2026	39.5	42	measured in 88 % of hours · provisional · 2 days without data from the station
December 2025	28.3	32.9	measured in 100 % of hours · verified
November 2025	too few readings	32.6	measured in 48 % of hours · verified · 4 days without data from the station

NO₂ by year

Yardstick: legal limits in the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19, 3/21)

Measure	2026*	2025	2024	2023
Days above 85 µg/m³ (none allowed)	0²	0²	0²	0²
Hours above 200 µg/m³ (allowed 18)	0²	0²	0²	0²
Hours above 400 µg/m³, three hours in a row (alert threshold)	0	0	0	0
Annual average, µg/m³ (legal limit 40)	too few	too few	too few	too few
Highest daily average, µg/m³	66January 13	67January 2	67January 23	48February 12
Highest hourly value, µg/m³	110August 11	118February 10	90January 23	78February 11
Hours measured	80 %	89 %	69 %	78 %
Days without any reading from the station	46	7	2	0

* 2026 up to October 6; the average since the start of the year is not yet an annual average.

The monitoring networks have not yet finally verified this year’s data. The EEA publishes verified values once a year.

² Too few readings to compare with the number allowed: the figure covers only what was measured.

■ and a figure in red: more than is allowed for the whole year.

There is no allowed number for the warning and alert thresholds: every such hour or day is in red.

The column for 2023 is shown on wider screens.

Compared with the new EU rules and the WHO recommendation

EU from 2030: daily 50 µg/m³, 18 days allowed. In 2023 there were 0 such days.
WHO 2021: daily 25 µg/m³, at most three to four days a year. In 2023 there were 47 such days.

Sources: Directive (EU) 2024/2881, Annex I; WHO global air quality guidelines 2021, table 0.1. Checked against the texts on 7 October 2026.

Ozone O₃

18.5

Nowµg/m³

Measured at 21:00

57.3

Last 24 hoursµg/m³

measured in 92 % of hours · provisional

54.1

Last 7 daysµg/m³

measured in 100 % of hours · provisional

too few readings

Last 30 days

measured in 49 % of hours · provisional

too few readings

Last 12 months

measured in 77 % of hours · 2 months with too few readings · provisional

Days in 2023: O₃, 8-hour average above 120 µg/m³

113 days above the limit.

above the limit
below the limit
too few readings for the day
no O₃ data in the EEA database

Days above the limit with values (113)

Apr 21 136
Apr 22 147
Apr 23 141
Apr 24 136
Apr 25 130
Apr 27 134
Apr 28 127
Apr 29 141
May 1 125
May 5 125
May 6 132
May 7 131
May 16 121
May 23 136
May 24 133
May 25 130
May 29 127
May 30 124
Jun 4 121
Jun 7 122
Jun 13 128
Jun 18 133
Jun 19 139
Jun 20 146
Jun 21 144
Jun 22 164
Jun 24 123
Jun 26 133
Jun 27 142
Jun 28 133
Jun 30 122
Jul 2 134
Jul 3 120
Jul 5 135
Jul 7 121
Jul 8 136
Jul 9 141
Jul 10 149
Jul 11 150
Jul 12 151
Jul 13 143
Jul 14 127
Jul 15 151
Jul 16 156
Jul 17 162
Jul 18 164
Jul 19 144
Jul 20 133
Jul 21 133
Jul 22 123
Jul 23 131
Jul 24 138
Jul 25 131
Jul 28 126
Jul 29 125
Jul 30 124
Aug 1 124
Aug 3 129
Aug 4 141
Aug 5 128
Aug 10 123
Aug 12 125
Aug 13 128
Aug 14 131
Aug 15 143
Aug 16 132
Aug 17 131
Aug 18 137
Aug 19 125
Aug 20 128
Aug 21 147
Aug 22 152
Aug 24 173
Aug 25 161
Aug 26 157
Aug 27 154
Aug 28 163
Aug 29 154
Aug 30 127
Sep 1 129
Sep 2 142
Sep 3 153
Sep 4 126
Sep 5 124
Sep 6 141
Sep 7 145
Sep 8 154
Sep 9 142
Sep 10 146
Sep 11 155
Sep 12 161
Sep 13 148
Sep 14 143
Sep 16 125
Sep 17 129
Sep 19 135
Sep 20 128
Sep 22 130
Sep 26 128
Sep 27 136
Sep 28 131
Sep 29 126
Sep 30 147
Oct 1 126
Oct 20 125
Oct 21 129
Oct 25 127
Oct 31 141
Nov 2 123
Nov 3 139
Nov 5 130
Dec 1 126
Dec 2 147

Values in µg/m³, limit 120 µg/m³.

Months of 2023

Month	Days above 120	Average	Highest 8 h
January	0	29	71
February	0	36	77
March	0	49	109
April	8 above the number allowed	70	147
May	10 above the number allowed	75	136
June	13 above the number allowed	81	164
July	25 above the number allowed	94	164
August	23 above the number allowed	92	173
September	24 above the number allowed	88	161
October	5 above the number allowed	67	141
November	3 above the number allowed	58	139
December	2 above the number allowed	47	147

Values in µg/m³. ■ marks a month with at least one day above the limit; the number allowed applies to the whole year. “No readings”: days on which not a single reading came from the station.

measuredmodel estimate, not counted

Last 7 days, every hour: O₃ in µg/m³

Values as a table

Hour to	µg/m³	Note
Wednesday, 10/7
22:00	48	model estimate, not counted
21:00	18.5
20:00	36.4
19:00	55.7
18:00	91.9
17:00	120
16:00	124.6
15:00	133.2
14:00	117.4
13:00	98.5
12:00	66.6
11:00	52.7
10:00	34.3
09:00	22.7
08:00	16.3
07:00	24.4
06:00	36
05:00	38.6
04:00	40.7
03:00	40.7
02:00	40.2
01:00	31.5
Tuesday, 10/6
00:00	20.4
23:00	14.8
22:00	14.1
21:00	16.8
20:00	28.8
19:00	40.1
18:00	81.2
17:00	135.7
16:00	142.6
15:00	149.4
14:00	157.1
13:00	124.2
12:00	89.7
11:00	52.9
10:00	34.7
09:00	20.2
08:00	15.5
07:00	24.3
06:00	36.7
05:00	39.2
04:00	40.8
03:00	39.2
02:00	27.6
01:00	20.1
Monday, 10/5
00:00	15.5
23:00	29.5
22:00	32.9
21:00	27.1
20:00	47.6
19:00	69.2
18:00	97.4
17:00	101.3
16:00	108.9
15:00	107.5
14:00	96
13:00	89
12:00	81.9
11:00	63.1
10:00	42
09:00	23.5
08:00	17.9
07:00	23.7
06:00	36.2
05:00	42.8
04:00	42.4
03:00	45.2
02:00	45.8
01:00	35
Sunday, 10/4
00:00	23.8
23:00	18.3
22:00	18.5
21:00	26.2
20:00	39.6
19:00	83.5
18:00	104.1
17:00	110.5
16:00	109.5
15:00	111.1
14:00	103.4
13:00	87.9
12:00	85.8
11:00	61.7
10:00	51.9
09:00	38.8
08:00	32.9
07:00	33.6
06:00	38.1
05:00	42.8
04:00	41.7
03:00	42
02:00	40.9
01:00	28.2
Saturday, 10/3
00:00	19.3
23:00	16.6
22:00	24.1
21:00	30.8
20:00	42.7
19:00	75.7
18:00	97.8
17:00	107.4
16:00	107.4
15:00	114.9
14:00	102.3
13:00	93.8
12:00	71.1
11:00	69.7
10:00	51.2
09:00	31.5
08:00	23.6
07:00	29.6
06:00	35.4
05:00	39.2
04:00	38.8
03:00	33.3
02:00	22.4
01:00	18.1
Friday, 10/2
00:00	14.6
23:00	23.7
22:00	19.2
21:00	17.4
20:00	23.2
19:00	74.1
18:00	92.4
17:00	99.4
16:00	100.6
15:00	100.1
14:00	98
13:00	77.2
12:00	61.9
11:00	55.3
10:00	37.5
09:00	25.6
08:00	15.4
07:00	22
06:00	34.5
05:00	37.4
04:00	42.7
03:00	41.4
02:00	39.3
01:00	31.1
Thursday, 10/1
00:00	29.3
23:00	17.4
22:00	27.8
21:00	31.5
20:00	43.5
19:00	79.5
18:00	92.2
17:00	96.1
16:00	97.8
15:00	102.5
14:00	99
13:00	91
12:00	88.1
11:00	56.2
10:00	34.9
09:00	20.7
08:00	15.5
07:00	18.6
06:00	33
05:00	35.1
04:00	37.6
03:00	39.5
02:00	35.5
01:00	25.3

too few readingstarget value, 120 µg/m³no data from the station

Last 30 days, highest 8-hour average of the day: O₃ in µg/m³

Values as a table

Day	µg/m³	Note
Tue, 10/6	116.6	provisional
Mon, 10/5	93.9	provisional
Sun, 10/4	99.5	provisional
Sat, 10/3	96.3	provisional
Fri, 10/2	88	provisional
Thu, 10/1	93.3	provisional
Wed, 9/30	92.4	provisional
Tue, 9/29	100.9	provisional
Mon, 9/28	98.7	provisional
Sun, 9/27	86.3	provisional
Sat, 9/26	75.7	provisional
Fri, 9/25	74.7	provisional
Thu, 9/24	66.3	provisional
Wed, 9/23	67.7	provisional
Tue, 9/22		too few readings
Mon, 9/21		no data from the station
Sun, 9/20		no data from the station
Sat, 9/19		no data from the station
Fri, 9/18		no data from the station
Thu, 9/17		no data from the station
Wed, 9/16		no data from the station
Tue, 9/15		no data from the station
Mon, 9/14		no data from the station
Sun, 9/13		no data from the station
Sat, 9/12		no data from the station
Fri, 9/11		no data from the station
Thu, 9/10		no data from the station
Wed, 9/9		no data from the station
Tue, 9/8		no data from the station
Mon, 9/7		no data from the station

Last 12 monthsthis month so fara year earliermonth with days without data from the station

Last 12 months, monthly average: O₃ in µg/m³

Values as a table

Month	µg/m³	a year earlier	Note
October 2026 so far	54.1	40.8	measured in 100 % of hours · provisional · year before: same days
September 2026	too few readings	40.9	measured in 30 % of hours · provisional · 20 days without data from the station
August 2026	86.5	57.9	measured in 97 % of hours · provisional
July 2026	too few readings	65.4	measured in 74 % of hours · provisional · 6 days without data from the station
June 2026	75.1	70.9	measured in 93 % of hours · provisional · 1 day without data from the station
May 2026	too few readings	57.4	measured in 60 % of hours · provisional · 1 day without data from the station
April 2026	too few readings	60.1	measured in 38 % of hours · provisional · 4 days without data from the station
March 2026	53.5	51.7	measured in 75 % of hours · provisional · 7 days without data from the station
February 2026	33.6	29	measured in 81 % of hours · provisional · 5 days without data from the station
January 2026	26.4	26.9	measured in 88 % of hours · provisional · 2 days without data from the station
December 2025	14	25.6	measured in 100 % of hours · verified
November 2025	17.7	21.5	measured in 84 % of hours · verified · 4 days without data from the station

O₃ by year

Yardstick: legal limits in the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19, 3/21)

Measure	2026*	2025	2024	2023
Days with 8-hour average above 120 µg/m³ (target value 25)	≥ 32	3	79	113
Annual average, µg/m³	too few	44	59.9	66.3
Highest 8-hour average, µg/m³	154August 10	134June 26	168April 9	173August 24
Hours measured	71 %	98 %	98 %	95 %
Days without any reading from the station	46	7	2	0

* 2026 up to October 6; the average since the start of the year is not yet an annual average.

The monitoring networks have not yet finally verified this year’s data. The EEA publishes verified values once a year.

≥ means at least: more than a tenth of the days or hours are missing, so the real number may be higher.

■ and a figure in red: more than is allowed for the whole year.

The column for 2023 is shown on wider screens.

The worst days of 2023

Day	Highest 8 h	Times the limit
Aug 24, 2023	173	1.4 ×
Jun 22, 2023	164	1.4 ×
Jul 18, 2023	164	1.4 ×
Aug 28, 2023	163	1.4 ×
Jul 17, 2023	162	1.4 ×

Daily average in µg/m³, daily limit 120 µg/m³. Days with the same unverified value over many hours are not on this list.

Sulphur dioxide SO₂

42.5

Nowµg/m³

Measured at 21:00

45.9

Last 24 hoursµg/m³

measured in 92 % of hours · provisional

43.4

Last 7 daysµg/m³

measured in 100 % of hours · provisional

too few readings

Last 30 days

measured in 49 % of hours · provisional

too few readings

Last 12 months

measured in 83 % of hours · 1 month with too few readings · provisional

Days in 2023: SO₂, daily average above 125 µg/m³

17 days above the limit.

above the limit
below the limit
too few readings for the day
no SO₂ data in the EEA database

Days above the limit with values (17)

Jan 4 171
Jan 8 138
Jan 12 144
Jan 16 128
Jan 31 151
Feb 1 176
Feb 10 143
Feb 11 179
Feb 12 239
Feb 13 160
Feb 14 149
Feb 15 154
Feb 16 198
Feb 17 167
Feb 18 157
Mar 2 129
Mar 5 135

Values in µg/m³, limit 125 µg/m³.

Months of 2023

Month	Days above 125	Hours above 350	Average	Highest day
January	5 above the number allowed	0	96	171
February	10 above the number allowed	6	117	239
March	2 above the number allowed	0	80	135
April	0	0	61	89
May	0	0	51	91
June	0	1	48	93
July	0	1	35	94
August	0	0	6	39
September	0	0	6	13
October	0	0	11	49
November	0	0	20	51
December	0	0	34	69

Values in µg/m³. ■ marks a month with at least one day above the limit; the number allowed applies to the whole year. “No readings”: days on which not a single reading came from the station.

measured

Last 7 days, every hour: SO₂ in µg/m³

Values as a table

Hour to	µg/m³	Note
Wednesday, 10/7
21:00	42.5
20:00	36.1
19:00	43.1
18:00	45.3
17:00	74.6
16:00	69.9
15:00	53.9
14:00	64.5
13:00	94.7
12:00	90.8
11:00	39.4
10:00	38.9
09:00	34.6
08:00	29.5
07:00	28.1
06:00	28
05:00	28.5
04:00	29.7
03:00	31
02:00	33.3
01:00	35.8
Tuesday, 10/6
00:00	38.1
23:00	43
22:00	47.7
21:00	49.8
20:00	58
19:00	48.7
18:00	43.9
17:00	54.4
16:00	52.2
15:00	74.9
14:00	128.3
13:00	99.4
12:00	99
11:00	43.6
10:00	37.9
09:00	33.3
08:00	28.9
07:00	27.7
06:00	27.5
05:00	29.1
04:00	30.4
03:00	32.9
02:00	35.8
01:00	40.2
Monday, 10/5
00:00	43.9
23:00	51.1
22:00	57.5
21:00	65.2
20:00	76.1
19:00	83
18:00	97.6
17:00	119.4
16:00	56.4
15:00	67.1
14:00	84.9
13:00	101.6
12:00	113.9
11:00	38.6
10:00	34.7
09:00	35.8
08:00	28.5
07:00	26.6
06:00	26.7
05:00	28.6
04:00	28.9
03:00	30.8
02:00	33
01:00	37.9
Sunday, 10/4
00:00	43.4
23:00	45.8
22:00	46.7
21:00	48.5
20:00	48
19:00	52.4
18:00	64.3
17:00	71.8
16:00	59.1
15:00	49
14:00	104.2
13:00	124.2
12:00	115.3
11:00	35.5
10:00	32
09:00	29.9
08:00	23.9
07:00	21.9
06:00	21.7
05:00	22.5
04:00	22.9
03:00	24.1
02:00	25.1
01:00	28.6
Saturday, 10/3
00:00	31.4
23:00	36.4
22:00	45.9
21:00	34.2
20:00	30.2
19:00	24.5
18:00	23.1
17:00	23.6
16:00	24.7
15:00	69.1
14:00	120.5
13:00	109.2
12:00	83.3
11:00	37.7
10:00	38.5
09:00	38.2
08:00	25.9
07:00	24.5
06:00	25.2
05:00	25.4
04:00	26.3
03:00	26.9
02:00	28.1
01:00	31
Friday, 10/2
00:00	33.3
23:00	34.1
22:00	34.4
21:00	34.5
20:00	31.2
19:00	30.6
18:00	25
17:00	23.4
16:00	29.4
15:00	87
14:00	90
13:00	69.3
12:00	81.4
11:00	73
10:00	30.5
09:00	28.8
08:00	26.2
07:00	25
06:00	24.5
05:00	25.1
04:00	25.5
03:00	25.5
02:00	26.4
01:00	26.9
Thursday, 10/1
00:00	29
23:00	30.4
22:00	31.4
21:00	32.3
20:00	27.2
19:00	24.2
18:00	23.4
17:00	23.8
16:00	28
15:00	86.2
14:00	67.9
13:00	29.8
12:00	42
11:00	37.7
10:00	30.7
09:00	25.5
08:00	25.6
07:00	25.4
06:00	25.7
05:00	25.6
04:00	26.6
03:00	26.2
02:00	26.6
01:00	26.6

too few readingslegal daily limit, 125 µg/m³no data from the station

Last 30 days, daily average: SO₂ in µg/m³

Values as a table

Day	µg/m³	Note
Tue, 10/6	50.2	provisional
Mon, 10/5	57	provisional
Sun, 10/4	48.4	provisional
Sat, 10/3	41	provisional
Fri, 10/2	39.2	provisional
Thu, 10/1	32.4	provisional
Wed, 9/30	35.4	provisional
Tue, 9/29	34.1	provisional
Mon, 9/28	51.4	provisional
Sun, 9/27	32.1	provisional
Sat, 9/26	33.1	provisional
Fri, 9/25	25.2	provisional
Thu, 9/24	62.9	provisional
Wed, 9/23	24.7	provisional
Tue, 9/22		too few readings
Mon, 9/21		no data from the station
Sun, 9/20		no data from the station
Sat, 9/19		no data from the station
Fri, 9/18		no data from the station
Thu, 9/17		no data from the station
Wed, 9/16		no data from the station
Tue, 9/15		no data from the station
Mon, 9/14		no data from the station
Sun, 9/13		no data from the station
Sat, 9/12		no data from the station
Fri, 9/11		no data from the station
Thu, 9/10		no data from the station
Wed, 9/9		no data from the station
Tue, 9/8		no data from the station
Mon, 9/7		no data from the station

Last 12 monthsthis month so fara year earlierlegal annual limit, 50 µg/m³month with days without data from the station

Last 12 months, monthly average: SO₂ in µg/m³

Values as a table

Month	µg/m³	a year earlier	Note
October 2026 so far	44.7	37.8	measured in 100 % of hours · provisional · year before: same days
September 2026	too few readings	43.2	measured in 30 % of hours · provisional · 20 days without data from the station
August 2026	37.5	43.6	measured in 97 % of hours · provisional
July 2026	too few readings	36.8	measured in 74 % of hours · provisional · 6 days without data from the station
June 2026	22.3	33.5	measured in 93 % of hours · provisional · 1 day without data from the station
May 2026	19.5	30.6	measured in 94 % of hours · provisional · 1 day without data from the station
April 2026	20.1	32.5	measured in 79 % of hours · provisional · 4 days without data from the station
March 2026	40	51.4	measured in 75 % of hours · provisional · 7 days without data from the station
February 2026	49.2	98.7	measured in 81 % of hours · provisional · 5 days without data from the station
January 2026	103.4	149.2	measured in 88 % of hours · provisional · 2 days without data from the station
December 2025	127.8	128	measured in 100 % of hours · verified
November 2025	93.8	114.1	measured in 84 % of hours · verified · 4 days without data from the station

SO₂ by year

Yardstick: legal limits in the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19, 3/21)

Measure	2026*	2025	2024	2023
Days above 125 µg/m³ (allowed 3)	≥ 10 above the number allowed	40 above the number allowed	15 above the number allowed	17 above the number allowed
Hours above 350 µg/m³ (allowed 24)	≥ 18²	180 above the number allowed	105 above the number allowed	8
Hours above 500 µg/m³, three hours in a row (alert threshold)	0	44 above the number allowed	52 above the number allowed	0
Annual average, µg/m³ (legal limit 50)	too few	67.2 above the number allowed	43.4	47.1
Highest daily average, µg/m³	288January 22	610January 19	861December 29	239February 12
Highest hourly value, µg/m³	585January 1	1,358January 19	1,371December 29	390February 16
Hours measured	80 %	98 %	93 %	99 %
Days without any reading from the station	46	7	2	0

* 2026 up to October 6; the average since the start of the year is not yet an annual average.

The monitoring networks have not yet finally verified this year’s data. The EEA publishes verified values once a year.

≥ means at least: more than a tenth of the days or hours are missing, so the real number may be higher.

² Too few readings to compare with the number allowed: the figure covers only what was measured.

■ and a figure in red: more than is allowed for the whole year.

There is no allowed number for the warning and alert thresholds: every such hour or day is in red.

The column for 2023 is shown on wider screens.

Compared with the new EU rules and the WHO recommendation

EU from 2030: daily 50 µg/m³, 18 days allowed. In 2023 there were 147 such days.
WHO 2021: daily 40 µg/m³, at most three to four days a year. In 2023 there were 201 such days.
EU from 2030: annual average 20 µg/m³. Average in 2023: 47 µg/m³.

Sources: Directive (EU) 2024/2881, Annex I; WHO global air quality guidelines 2021, table 0.1. Checked against the texts on 7 October 2026.

The worst days of 2023

Day	Average	Times the limit
Feb 12, 2023	239	1.9 ×
Feb 16, 2023	198	1.6 ×
Feb 11, 2023	179	1.4 ×
Feb 1, 2023	176	1.4 ×
Jan 4, 2023	171	1.4 ×

Daily average in µg/m³, daily limit 125 µg/m³. Days with the same unverified value over many hours are not on this list.

Outages in the last 12 months

Every period of at least 24 hours in which no reading arrived from this station.

Days without a reading: 60

11 outages, 1,440 hours in total in the last 12 months.

Timeline of outages from October 7, 2025 to today

From	To	Duration
Sep 1, 2026 09:00	Sep 22, 2026 09:00	21 days
Jul 13, 2026 22:00	Jul 20, 2026 09:00	6 days
Jul 1, 2026 09:00	Jul 2, 2026 09:00	24 hours
Jun 9, 2026 05:00	Jun 11, 2026 11:00	2 days
May 23, 2026 00:00	May 24, 2026 08:00	32 hours
Apr 10, 2026 04:00	Apr 13, 2026 11:00	3 days
Apr 4, 2026 12:00	Apr 7, 2026 09:00	3 days
Feb 23, 2026 14:00	Mar 8, 2026 15:00	13 days
Jan 26, 2026 14:00	Jan 28, 2026 14:00	2 days
Jan 9, 2026 14:00	Jan 11, 2026 11:00	45 hours
Nov 21, 2025 14:00	Nov 26, 2025 11:00	5 days

Calculated from the hourly values the EEA publishes. If late values arrive afterwards, an outage gets shorter or disappears.

Who is responsible

Air quality in the Federation of BiH is monitored by three networks of stations: the federal, the cantonal and the municipal one (Air Protection Act, Official Gazette FBiH 72/24, Art. 12 to 16).

Federal Hydrometeorological Institute (FHMZ): Runs the federal network, collects the data of all networks and publishes it. It issues a report every month and, every year by 31 July, the annual air quality report (Art. 14, 19 and 63).
Canton: Sets up the cantonal network and is responsible for the measures. When limit values are exceeded, it adopts an air quality plan. When warning or alert thresholds are at risk of being exceeded, it adopts a short-term intervention plan. When the information threshold or a concentration dangerous to health is exceeded, it informs the public (Art. 15, 22, 25, 27 and 61). In Zenica-Doboj Canton the Ministry of Physical Planning, Transport, Communications and Environmental Protection is responsible for environmental protection. The 2024 intervention plan was adopted by the Government of the canton.
Municipality: May run its own stations with the consent of the canton and must publish their results (Art. 16 and 17). Under the Zenica-Doboj Canton intervention plan (Official Gazette ZDK 3/24, Art. 3), the mayor of the municipality or city declares readiness based on the report of the authorised expert institution, and warning and alert based on the decision of the operational headquarters.
Inspectorates: The inspectorates of the Federation, the canton and the municipality supervise the law and the measures, each within its remit (Art. 71).

What the law requires when a limit is exceeded

A limit value is not a recommendation. The deadline for meeting the limit values for sulphur dioxide, nitrogen dioxide and particulate matter expired on 1 January 2021. Since then only the number of exceedances that the Pravilnik allows applies (Official Gazette FBiH 1/12, Annex X). The Air Protection Act adds that limit values, once met, must not be exceeded again (Art. 5(4)).

The law allows: for PM10 at most 35 days a year above 50 µg/m³, for sulphur dioxide at most 24 hours above 350 µg/m³ and at most 3 days above 125 µg/m³, for nitrogen dioxide at most 18 hours above 200 µg/m³ and no day with a daily average above 85 µg/m³ (Annex X).

When limits are exceeded, the canton adopts an air quality plan with measures that shorten the period of exceedance. The plan is published within eight days of adoption (Art. 8, 25, 26 and 63).

The alert thresholds are 500 µg/m³ for sulphur dioxide and 400 µg/m³ for nitrogen dioxide over three hours in a row, and 300 µg/m³ for PM10 and 280 µg/m³ for PM2.5 as a daily average (Pravilnik, Annex XIV, amended in Official Gazette FBiH 3/21). When such a situation threatens, the canton must have a short-term intervention plan. It can restrict traffic, construction work, the operation of plants and heating (Art. 27 and 28).

When the information threshold or a concentration dangerous to health is exceeded, the competent cantonal authorities inform the public through radio, television, newspapers and the internet: where, since when, how much was measured, what is expected and how to protect oneself (Art. 61 and 62).

In Zenica-Doboj Canton the procedure is set by the intervention plan (Official Gazette ZDK 3/24) in three stages: readiness, warning and alert. An alert also requires a forecast of stable weather for the next 48 hours.

The canton also has an Action Plan for Air Quality Protection from 2020 (Official Gazette ZDK 9/20), adopted under the earlier law. We could not tell from the published decision how long it applies.

We show measured values only. Whether an episode has been declared is decided by the competent authorities, who publish it on their own pages.

The limit values in BiH match the EU rules of 2008. Since 2021 the World Health Organization has recommended much lower values, for PM10 45 µg/m³ a day and 15 µg/m³ a year. From 2030 the EU lowers the annual PM10 limit to 20 µg/m³ (Directive (EU) 2024/2881).

We checked the rules against the published texts on 7 October 2026.

Where the data comes from

Measured by Federal Hydrometeorological Institute. We take the values from the European Environment Agency (EEA) under the CC BY 4.0 licence.

Values marked provisional have not been fully checked by the network yet. The EEA publishes verified data for the previous year once a year, usually by the end of September.

An hourly value is the average of one hour. We show the end of the hour: the value to 18:00 was measured from 17:00 to 18:00.

A day runs from midnight to midnight local time.

We only show an average when at least three out of four hours in the period have a reading. The EU air quality directive requires this for daily averages, and we apply the same rule to longer periods. We compare an annual average with the EU limit only once 90 % of hours are measured, as the directive requires. For 12 months and for a year we ask for more: if less than 90 % of hours are measured, every full calendar month needs readings for at least half of its hours. Otherwise a whole season could be missing from the average, such as summer, when ozone is highest.

We do not call a difference of up to 10 % a change, nor one of up to 1 µg/m³ at low levels, because weather and measurement uncertainty alone cause differences that size.

When a station sends no reading, the EEA sometimes fills the hour with a model estimate. We draw those hours dashed and leave them out of every average.

The limits are the legal limits of the Federation of BiH (Pravilnik, Official Gazette FBiH 1/12, 50/19 and 3/21, Annexes X and XIV). They match EU Directive 2008/50/EC. When more than a tenth of the days or hours are missing, the number of exceedances can only be higher, so we write “at least” in front of it.

How we measure

Other stations in Zenica

How to cite this page

Name samoEKO as the source and link to this page. The readings come from official stations, so please credit them too.

Source: samoEKO, Air quality, Zenica - Centar station, https://samoeko.com/en/luft/stanica/BA0037A, accessed 7 October 2026. Readings: official stations, via the European Environment Agency (EEA). The level is calculated by samoEKO.

Rules for reuse

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