SmogRank / History / City race
Cities in Czechia, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in Czechia for PM2.5 over the 30 days to 12 Jan 2025: Ostrava 30.8 µg/m³, Bohumín 30.2 µg/m³ and Havířov 29.0 µg/m³.
- 1OstravaMoravian-Silesian Region30.8
- 2BohumínMoravian-Silesian Region30.2
- 3HavířovMoravian-Silesian Region29.0
- 4StudénkaMoravian-Silesian Region27.2
- 5Frýdek-MístekMoravian-Silesian Region26.1
- 6PřerovOlomouc Region25.5
- 7OlomoucOlomouc Region23.8
- 8Valašské MeziříčíZlín23.7
- 9ZlínZlín23.1
- 10Moravská TřebováPardubice Region22.6
- 11Český TěšínMoravian-Silesian Region21.6
- 12TřinecMoravian-Silesian Region20.8
- 13ZnojmoSouth Moravian20.7
- 14OpavaMoravian-Silesian Region20.6
- 15BrnoSouth Moravian19.2
- 16BerounCentral Bohemia19.1
- 17DěčínÚstí nad Labem Region18.5
- 18ŽideniceSouth Moravian18.2
- 19SlatinaSouth Moravian18.2
- 20KroměřížZlín18.0
+ 16 more cities, 17.7 µg/m³ and below
Not counted on this day, too few days measured: Náchod since 10 Jan 2025.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.