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 14 Jan 2025: Ostrava 32.6 µg/m³, Bohumín 31.9 µg/m³ and Havířov 30.4 µg/m³.
- 1OstravaMoravian-Silesian Region32.6
- 2BohumínMoravian-Silesian Region31.9
- 3HavířovMoravian-Silesian Region30.4
- 4StudénkaMoravian-Silesian Region28.5
- 5Frýdek-MístekMoravian-Silesian Region27.3
- 6PřerovOlomouc Region26.4
- 7Valašské MeziříčíZlín24.8
- 8OlomoucOlomouc Region24.5
- 9ZlínZlín24.0
- 10Moravská TřebováPardubice Region23.5
- 11Český TěšínMoravian-Silesian Region22.6
- 12TřinecMoravian-Silesian Region21.8
- 13ZnojmoSouth Moravian21.3
- 14BerounCentral Bohemia20.0
- 15BrnoSouth Moravian19.8
- 16DěčínÚstí nad Labem Region19.3
- 17ŽideniceSouth Moravian18.8
- 18SlatinaSouth Moravian18.8
- 19KroměřížZlín18.6
- 20TepliceÚstí nad Labem Region18.4
+ 15 more cities, 16.5 µg/m³ and below
Not counted on this day, too few days measured: Opava since 14 Jan 2025 and 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.