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Air at the Zenica - Vranduk station

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

Network: Federal Hydrometeorological Institute · Station code: BA0051A

This year, up to yesterday (October 6)

at least

6 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.

The number allowed for the whole year has been exceeded.

at least 3 days more than allowed

at least

17 days

with a daily average of particulate matter PM10 above the legal limit of 50 µg/m³.

Readings are missing for part of the period, so the real number may be higher.

Worst day: January 22, 2026, SO₂ 292 µg/m³ as a daily average, 2.3 times the limit.

At least 2 days with a daily average of PM10 above 150 µg/m³, the warning threshold in the Federation of BiH.

These are measured values only. Whether a warning or alert episode has been declared is decided and published by the competent authorities.

Also: at least 3 hours above the legal hourly limit for SO₂ of 350 µg/m³ (too few readings to compare with the allowed number).

Also: at least 1 day with an 8-hour average of ozone (O₃) above the target value of 120 µg/m³.

Daily average for 177 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

Fair

Air now · Measured at 19:00

Latest values

Latest value: 19:00

Readings
PollutantValueLevel
PM1021.6 µg/m³Fair
O₃42.4 µg/m³Good
SO₂16.3 µg/m³Good

How the air is changing

Over the last seven days there was more PM10, PM2.5, O₃, and SO₂ in the air than the week before.

  • PM10: average 29.3 µg/m³, week before 19.1 µg/m³
  • PM2.5: average 16.3 µg/m³, week before 10.3 µg/m³
  • O₃: average 25.5 µg/m³, week before 21 µg/m³
  • SO₂: average 20.1 µg/m³, week before 10.3 µg/m³

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

  • PM10: too few readings to compare
  • PM2.5: too few readings to compare
  • O₃: too few readings to compare
  • SO₂: too few readings to compare

Show

Sulphur dioxide SO₂

16.3

Nowµg/m³

Measured at 19:00

28.4

Last 24 hoursµg/m³

measured in 88 % of hours · provisional

20.1

Last 7 daysµg/m³

measured in 100 % of hours · provisional

too few readings

Last 30 days

measured in 42 % of hours · provisional

too few readings

Last 12 months

measured in 78 % of hours · 3 months with too few readings · provisional

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

41 days above the limit.

1102031JanJan 1: 161 µg/m³, above the limitJan 2: 176 µg/m³, above the limitJan 3: 168 µg/m³, above the limitJan 5: 184 µg/m³, above the limitJan 6: 207 µg/m³, above the limitJan 7: 217 µg/m³, above the limitJan 8: 219 µg/m³, above the limitJan 13: 186 µg/m³, above the limitJan 15: 194 µg/m³, above the limitFebFeb 1: 159 µg/m³, above the limitFeb 11: 140 µg/m³, above the limitFeb 12: 213 µg/m³, above the limitFeb 16: 200 µg/m³, above the limitFeb 17: 163 µg/m³, above the limitFeb 21: 138 µg/m³, above the limitMarMar 6: 139 µg/m³, above the limitAprMayJunJun 30: 151 µg/m³, above the limitJulAugSepOctOct 8: 192 µg/m³, above the limitOct 12: 152 µg/m³, above the limitNovNov 9: 132 µg/m³, above the limitNov 12: 144 µg/m³, above the limitNov 13: 203 µg/m³, above the limitNov 14: 126 µg/m³, above the limitNov 16: 292 µg/m³, above the limitNov 19: 140 µg/m³, above the limitNov 20: 229 µg/m³, above the limitNov 24: 218 µg/m³, above the limitNov 27: 287 µg/m³, above the limitNov 28: 134 µg/m³, above the limitDecDec 5: 312 µg/m³, above the limitDec 9: 261 µg/m³, above the limitDec 10: 342 µg/m³, above the limitDec 11: 403 µg/m³, above the limitDec 12: 308 µg/m³, above the limitDec 13: 170 µg/m³, above the limitDec 17: 213 µg/m³, above the limitDec 18: 382 µg/m³, above the limitDec 19: 336 µg/m³, above the limitDec 20: 282 µg/m³, above the limitDec 21: 394 µg/m³, above the limitDec 24: 264 µg/m³, 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 (41)
  1. Jan 1 161
  2. Jan 2 176
  3. Jan 3 168
  4. Jan 5 184
  5. Jan 6 207
  6. Jan 7 217
  7. Jan 8 219
  8. Jan 13 186
  9. Jan 15 194
  10. Feb 1 159
  11. Feb 11 140
  12. Feb 12 213
  13. Feb 16 200
  14. Feb 17 163
  15. Feb 21 138
  16. Mar 6 139
  17. Jun 30 151
  18. Oct 8 192
  19. Oct 12 152
  20. Nov 9 132
  21. Nov 12 144
  22. Nov 13 203
  23. Nov 14 126
  24. Nov 16 292
  25. Nov 19 140
  26. Nov 20 229
  27. Nov 24 218
  28. Nov 27 287
  29. Nov 28 134
  30. Dec 5 312
  31. Dec 9 261
  32. Dec 10 342
  33. Dec 11 403
  34. Dec 12 308
  35. Dec 13 170
  36. Dec 17 213
  37. Dec 18 382
  38. Dec 19 336
  39. Dec 20 282
  40. Dec 21 394
  41. Dec 24 264

Values in µg/m³, limit 125 µg/m³.

Months of 2023

MonthDays above 125Hours above 350Highest dayNo readings
January9 above the number allowed22190
February6 above the number allowed102130
March1 above the number allowed21390
April00380
May00610
June1 above the number allowed21510
July02930
August01770
September03680
October2 above the number allowed101920
November10 above the number allowed322920
December12 above the number allowed914030

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.

Last 7 days, every hour: SO₂ in µg/m³highest 133 µg/m³, latest 16 µg/m³ (19:00)050100150ThuFriSatSunMonTueWedlatest 16 (19:00)
measured
Last 7 days, every hour: SO₂ in µg/m³
Values as a table
Hour toµg/m³Note
Wednesday, 10/7
19:0016.3
18:0013.5
17:0012.3
16:0013.7
15:0013.9
14:0024
13:0093
12:0079.3
11:0045.8
10:0040.6
09:0037.2
08:0028.4
07:0022
06:0018
05:0017.3
04:0018.4
03:0018.1
02:0019.8
01:0021
Tuesday, 10/6
00:0019.8
23:0024
22:0029.8
21:0033.1
20:0037.8
19:0039.4
18:0031.8
17:0054.9
16:0089
15:0096.3
14:0084.4
13:0061.5
12:0044.8
11:0034.6
10:0032.2
09:0021.6
08:0015.3
07:008.9
06:009
05:009.7
04:0010.7
03:0011.3
02:0011.7
01:0015
Monday, 10/5
00:0022
23:0027.9
22:0033.9
21:0041.7
20:0048
19:0054.8
18:0065.8
17:0072.1
16:00133.2
15:00122.8
14:00131.6
13:00125.1
12:0074.8
11:0032.4
10:0024.9
09:0021.1
08:0010
07:007.2
06:007.1
05:007.7
04:008.6
03:0010.2
02:0010.6
01:009.1
Sunday, 10/4
00:009.3
23:0014.1
22:0016.9
21:0018.6
20:0022.1
19:0025.7
18:0028.5
17:0032.4
16:0037.3
15:0031
14:0029.5
13:0025.1
12:0020.1
11:0019.7
10:0024.7
09:0013.4
08:006.6
07:006.3
06:004.9
05:004.5
04:005.8
03:006.1
02:004.7
01:003.7
Saturday, 10/3
00:004.1
23:003.4
22:003.2
21:003.4
20:004.6
19:003.5
18:003.4
17:003.6
16:004.2
15:003.7
14:004.6
13:007
12:0011.1
11:0013.2
10:0010.5
09:006.2
08:004.5
07:004.5
06:004.7
05:005.1
04:005.6
03:005.5
02:005.9
01:007.3
Friday, 10/2
00:007.5
23:007.6
22:008.4
21:009
20:0010.5
19:0011.1
18:0010.5
17:004.9
16:006.9
15:0018.7
14:0056.5
13:0028.7
12:0019
11:0020.7
10:0025.3
09:0015.8
08:006.1
07:005.6
06:005.7
05:005.2
04:005.6
03:005
02:004.6
01:005.1
Thursday, 10/1
00:005.1
23:005.1
22:004.5
21:004.7
20:004.3
19:004.5
18:004.3
17:005.1
16:005.2
15:0022.8
14:0064.8
13:0031.3
12:0015.8
11:0019
10:0020
09:0010
08:005.4
07:005.1
06:004.7
05:004.5
04:004.3
03:004.6
02:005
01:005.1
Wednesday, 9/30
00:004.8
Last 30 days, daily average: SO₂ in µg/m³highest 46 µg/m³, latest 34 µg/m³02040609/99/169/239/30latest 34
too few readingsno data from the station
Last 30 days, daily average: SO₂ in µg/m³
Values as a table
Dayµg/m³Note
Tue, 10/634.4provisional
Mon, 10/545.9provisional
Sun, 10/417.1provisional
Sat, 10/35.5provisional
Fri, 10/212.7provisional
Thu, 10/111.1provisional
Wed, 9/3013.9provisional
Tue, 9/2910.6provisional
Mon, 9/2814.9provisional
Sun, 9/275.6provisional
Sat, 9/267.1provisional
Fri, 9/254.7provisional
Thu, 9/24too few readings
Wed, 9/23no measurement
Tue, 9/22no measurement
Mon, 9/21no data from the station
Sun, 9/20no data from the station
Sat, 9/19no data from the station
Fri, 9/18no data from the station
Thu, 9/17no data from the station
Wed, 9/16no data from the station
Tue, 9/15no data from the station
Mon, 9/14no data from the station
Sun, 9/13no data from the station
Sat, 9/12no data from the station
Fri, 9/11no data from the station
Thu, 9/10no data from the station
Wed, 9/9no data from the station
Tue, 9/8no data from the station
Mon, 9/7no data from the station
Last 12 months, monthly average: SO₂ in µg/m³highest 96 µg/m³, latest 21 µg/m³050100150DecFebAprJunAugOcthighest 96latest 21
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
Monthµg/m³a year earlierNote
October 2026 so far21.19.9measured in 100 % of hours · provisional · year before: same days
September 2026too few readings13.6measured in 22 % of hours · provisional · 20 days without data from the station
August 2026too few readings12.2measured in 64 % of hours · provisional
July 2026too few readings12.2measured in 49 % of hours · provisional
June 2026too few readingstoo few readingsmeasured in 49 % of hours · provisional · 1 day without data from the station
May 202659.7too few readingsmeasured in 94 % of hours · provisional · 1 day without data from the station
April 202644.4too few readingsmeasured in 79 % of hours · provisional · 4 days without data from the station
March 202654.274.5measured in 99 % of hours · provisional
February 202656.196.8measured in 98 % of hours · provisional
January 202679.8123measured in 85 % of hours · provisional · 2 days without data from the station
December 202595.9measured in 100 % of hours · verified
November 202541.5measured in 99 % of hours · verified

SO₂ by year

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

Measure2026*20252023
Days above 125 µg/m³ (allowed 3)≥ 6 above the number allowed≥ 30 above the number allowed≥ 41 above the number allowed
Hours above 350 µg/m³ (allowed 24)≥ 3²≥ 71 above the number allowed≥ 155 above the number allowed
Hours above 500 µg/m³, three hours in a row (alert threshold)0≥ 21 above the number allowed≥ 17 above the number allowed
Annual average, µg/m³ (legal limit 50)too fewtoo fewtoo few
Highest daily average, µg/m³292January 22507January 1403December 11
Highest hourly value, µg/m³367January 22931January 20907June 30
Hours measured72 %85 %88 %
Days without any reading from the station2800

* 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.

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 50 µg/m³, 18 days allowed. In 2023 there were 121 such days.
  • WHO 2021: daily 40 µg/m³, at most three to four days a year. In 2023 there were 160 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.

The worst days of 2023

DayAverageTimes the limit
Dec 11, 20234033.2 ×
Dec 21, 20233943.2 ×
Dec 18, 20233823.1 ×
Dec 10, 20233422.7 ×
Dec 19, 20233362.7 ×

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: 36

8 outages, 854 hours in total in the last 12 months.

Timeline of outages from October 7, 2025 to today

FromToDuration
Sep 1, 2026 09:00Sep 22, 2026 09:0021 days
Jul 1, 2026 09:00Jul 2, 2026 09:0024 hours
Jun 9, 2026 05:00Jun 11, 2026 11:002 days
May 23, 2026 00:00May 24, 2026 08:0032 hours
Apr 10, 2026 04:00Apr 13, 2026 11:003 days
Apr 4, 2026 12:00Apr 7, 2026 09:003 days
Jan 26, 2026 15:00Jan 28, 2026 14:0047 hours
Jan 9, 2026 14:00Jan 11, 2026 11:0045 hours

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.

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

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