Information about air quality in the Czech Republic

SWRS - support table for announcement and cancellation of smog situations and regulations

Information on currently issued smog situations/regulations/alerts can be found here here

Updated: 2024-03-28 15:24 UTC

PM10 SO2 ►NO2◄ O3

SWRS areas for NO₂
►Agglomeration of Prague◄ Central Bohemia region South Bohemia region Plzeň region Northeast zone Northwest zone Vysočina region South Moravia region without agglomeration of Brno Agglomeration of Brno Central Moravia region Moravia and Silezia zone Agglomeration of Ostrava/Karviná/Frýdek-Místek
Situation No situation No situation No situation No situation No situation No situation No situation No situation No situation No situation No situation No situation
Warning No problem No problem No problem No problem No problem No problem No problem No problem No problem No problem No problem No problem

NO₂(nitrogen dioxide) - Agglomeration of Prague

   
Station Announcement Cancellation h:
Code Name Owner Increasing trends - only informative** conc. > 200 conc. > 400 Decreasing trends - only informative*** conc. < 200 conc. < 400  
 
ARIEA Praha 2-Riegrovy sady CHMI - - - - > 48 hrs > 48 hrs
ALIBA Praha 4-Libus CHMI - - - - > 48 hrs > 48 hrs
AKOBA Praha 8-Kobylisy CHMI - - - - > 48 hrs > 48 hrs
Number of stations 0/3 0/3 0/3 0/3 3/3 3/3
1h averages of NO2. The time is in UTC and corresponds to the end of the interval over which the concentration is averaged.
0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -24 -25 -26 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 -41 -42 -43 -44 -45 -46 -47 -48 -49  
28.03. 15:00 28.03. 14:00 28.03. 13:00 28.03. 12:00 28.03. 11:00 28.03. 10:00 28.03. 09:00 28.03. 08:00 28.03. 07:00 28.03. 06:00 28.03. 05:00 28.03. 04:00 28.03. 03:00 28.03. 02:00 28.03. 01:00 28.03. 00:00 27.03. 23:00 27.03. 22:00 27.03. 21:00 27.03. 20:00 27.03. 19:00 27.03. 18:00 27.03. 17:00 27.03. 16:00 27.03. 15:00 27.03. 14:00 27.03. 13:00 27.03. 12:00 27.03. 11:00 27.03. 10:00 27.03. 09:00 27.03. 08:00 27.03. 07:00 27.03. 06:00 27.03. 05:00 27.03. 04:00 27.03. 03:00 27.03. 02:00 27.03. 01:00 27.03. 00:00 26.03. 23:00 26.03. 22:00 26.03. 21:00 26.03. 20:00 26.03. 19:00 26.03. 18:00 26.03. 17:00 26.03. 16:00 26.03. 15:00 26.03. 14:00  
 
7.8 7.8 → 8.0 8.0 ↗ 5.4 5.4 → 5.0 5.0 → 5.4 5.4 → 6.3 6.3 → 7.3 7.3 ↘ 9.2 9.2 → 9.4 9.4 ↗ 8.0 8.0 →     4.6 4.6 ↘ 5.9 5.9 ↘ 9.9 9.9 ↗ 5.4 5.4 ↘ 9.8 9.8 ↘ 15.1 15.1 → 15.7 15.7 → 16.1 16.1 → 16.3 16.3 ↘ 20.3 20.3 → 20.1 20.1 ↗ 12.8 12.8 ↗ 10.7 10.7 ↗ 9.4 9.4 ↘ 11.3 11.3 ↗ 9.9 9.9 ↗ 8.6 8.6 ↘ 9.8 9.8 ↘ 12.4 12.4 → 13.0 13.0 ↘ 21.2 21.2 ↘ 41.9 41.9 →     20.5 20.5 ↗ 15.1 15.1 ↗ 10.5 10.5 ↘ 12.2 12.2 ↗ 11.1 11.1 ↘ 13.2 13.2 ↘ 14.9 14.9 ↘ 16.6 16.6 ↘ 19.1 19.1 ↘ 28.7 28.7 → 27.9 27.9 ↘ 32.5 32.5 ↗ 20.5 20.5 ↗ 10.9 10.9 → 10.7 10.7 ↗ 9.2 9.2 →
3.1 3.1 → 3.3 3.3 ↗ 2.1 2.1 → 2.7 2.7 → 2.5 2.5 → 3.4 3.4 → 4.2 4.2 → 4.8 4.8 ↘ 6.5 6.5 ↗ 5.2 5.2 ↗ 3.6 3.6 → 2.9 2.9 → 3.8 3.8 ↘ 7.8 7.8 ↗ 3.4 3.4 → 2.9 2.9 ↘ 4.2 4.2 ↘ 7.7 7.7 ↗ 5.7 5.7 ↘ 7.7 7.7 →     7.7 7.7 ↗ 6.1 6.1 → 5.5 5.5 → 4.6 4.6 → 4.8 4.8 → 4.6 4.6 → 4.0 4.0 → 4.8 4.8 ↘ 5.9 5.9 → 6.9 6.9 → 6.9 6.9 ↘ 9.8 9.8 ↘ 15.7 15.7 ↗ 9.9 9.9 ↗ 6.9 6.9 ↗ 3.6 3.6 → 2.7 2.7 → 3.6 3.6 → 3.3 3.3 ↘ 5.5 5.5 ↘ 6.7 6.7 ↗ 5.5 5.5 ↘ 13.4 13.4 →     16.8 16.8 ↗ 14.9 14.9 ↗ 6.3 6.3 → 5.7 5.7 → 4.8 4.8 →
9.0 9.0 → 9.6 9.6 ↗ 5.7 5.7 → 6.3 6.3 →     6.9 6.9 ↘ 8.0 8.0 ↘ 9.4 9.4 ↘ 13.0 13.0 ↗ 10.3 10.3 ↗ 5.4 5.4 → 4.8 4.8 ↘ 6.3 6.3 ↘ 9.9 9.9 ↗ 5.4 5.4 ↘ 9.6 9.6 ↗ 8.2 8.2 → 8.6 8.6 ↘ 10.7 10.7 ↘ 12.1 12.1 ↘ 18.0 18.0 ↗ 13.4 13.4 ↗ 10.5 10.5 → 10.1 10.1 ↗ 8.8 8.8 → 9.8 9.8 ↗ 7.3 7.3 →     8.0 8.0 ↘ 10.7 10.7 ↘ 14.7 14.7 ↘ 20.1 20.1 ↘ 28.7 28.7 ↗ 24.7 24.7 ↗ 12.1 12.1 ↗ 6.1 6.1 ↗ 5.0 5.0 → 5.0 5.0 → 5.2 5.2 ↘ 7.1 7.1 ↘ 8.6 8.6 → 9.4 9.4 → 9.6 9.6 → 10.3 10.3 ↘ 15.3 15.3 ↘ 18.4 18.4 ↗ 14.3 14.3 ↗ 9.2 9.2 → 8.8 8.8 ↗ 7.7 7.7 →


  • * Announcement of smog situation (regulation) is to be assessed if not issued yet. For more info see detailed legend (in Czech only).
  • ** Number of consecutive hours with increasing trends of1h average of. Counted since1h average exceeded 150µg/m³. For more info see detailed legend (in Czech only)
  • *** Number of consecutive hours with decreasing trends of 1h average of NO₂. Counted only if 1h average exceeded value 150µg/m³. before the first decreasing trend occurred. For more info see detailed legend (in Czech only).

Legend

   Color    Description
Exceedance of information threshold 200 µg/m³
Exceedance od regulatory threshold 400 µg/m³
No exceedance
Missing data


Notes

Smog situation for given region is announced in case when

  • at least on one measurement station representative for given region 1-hour average NO2 concentration exceeds information threshold value 200 µg.m⁻³ over three consecutive hours
  • and based on an evaluation of the forecast of meteorological conditions and pollution situation no decrease of the concentration below the information threshold value can be expected during the next 24 hours (i.e. concentrations exceeding the information threshold value are expected in next 24 hours on at least one station; this station does not have to be the same as one on which information threshold value was exceeded at the time of announcement).

Alert for public is announced for given area in case when at least on one measurement station representative for given region 1-hour average NO2 concentration exceeds regulatory threshold value 400 µg.m⁻³ over three consecutive hours. NO2 forecast is not considered. If the conditions for alert and regulation are met at the same time, only regulation is announced.

Regulation is announced for given region in case when

  • at least on half of the measurement stations representative for given region (on all stations if there are just two of them) 1-hour average NO2 concentration exceeds regulatory threshold value 400 µg.m⁻³ over three consecutive hours
  • and based on an evaluation of the forecast of meteorological conditions and pollution situation no decrease of the concentration below the regulatory threshold value can be expected during the next 24 hours (i.e. concentrations exceeding the regulatory threshold value are expected in next 24 hours on at least half of the stations (or on all stations if there are just two of them); these stations do not have to be the same as those on which regulatory threshold value was exceeded at the time of announcement).

Cancellation of regulation, smog situation and alerts

  • Regulation / alert / smog situation and is revoked if no measuring site representative for the given region reports the concentration of polluting substances above the corresponding threshold value and this state lasts continuously for at least 12 hours and no recurrent instance of exceeding the respective threshold value can be expected within the next 24 hours based on the meteorological forecast.
  • 12-hour time interval is being reduced up to 3 hours in a case when meteorological conditions cannot be assessed as leading to the smog situation and recurrent instance of exceeding the respective threshold value can almost be excluded in the next 24 hours in accordance with the meteorological forecast.