SmogRank / Czechia / Prague / Prague

Prague, month by month

Prague has a measured daily mean on 812 days since 1 January 2023. Its worst month was February 2025, at 92 US AQI (31.0 µg/m³), 201st of 2,633 cities on that month's world ranking. Its cleanest was September 2025, at 44 US AQI (8.0 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)85 days measured
Jan12 daysFeb13 daysMar11 daysApr17 daysMay19 daysJun5 daysJulnoneAug2 daysSep1 dayOct5 days
2025too few days for a mean (a year needs 256)201 days measured
Jan15 daysFeb92#201Mar14 daysApr19 daysMay15 daysJun5 daysJul14 daysAug54#1,027Sep44#1,244Oct10 daysNov16 daysDec56#974
2024too few days for a mean (a year needs 257)221 days measured
Jan71#282Feb52#730Mar15 daysApr48#1,210May51#970Jun2 daysJul52#859Aug1 daySepnoneOct11 daysNov63#386Dec60#540
202356 for the year305 days measured237th of 1,355 in the world
Jan54#407Feb62#331Mar57#150Apr56#263May55#312Jun56#581Jul53#631Aug19 daysSep56#335Oct54#268Nov20 daysDec21 days
Each square is a month's mean PM2.5 in US AQI from Prague's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Prague marked; each year, the year's.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

26 months
MonthWhy
Oct 20265 of 11 days measured; a month needs 8. The others: 6 with readings for part of the day (a day needs 18 hours).
Sep 20261 of 30 days measured; a month needs 21. The others: 29 with readings for part of the day (a day needs 18 hours).
Aug 20262 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jul 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 20265 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
May 202619 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Apr 202617 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Mar 202611 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Feb 202613 of 28 days measured; a month needs 20. The others: 15 with under 18 hours of readings or readings that failed our checks.
Jan 202612 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Nov 202516 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Oct 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Jul 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jun 20255 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
May 202515 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Apr 202519 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Mar 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jan 202515 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Oct 202411 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Jun 20242 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
Mar 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Dec 202321 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Nov 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Aug 202319 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Prague's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2025 9231.0 µg/m³20 of 28201stof 2,633Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
January 2024 7119.7 µg/m³27 of 31282ndof 2,385Europe, 27 January to 2 February 2024
Europe, 28 to 31 January 2024and 2 more
November 2024 6315.5 µg/m³27 of 30386thof 2,624Eastern Europe, 25 to 29 November 2024
Europe, November 2024and 1 more
February 2023 6215.2 µg/m³27 of 28331stof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
December 2024 6013.8 µg/m³24 of 31540thof 2,616Europe, 24 December 2024 to 3 January 2025
March 2023 5712.1 µg/m³27 of 31150thof 911Europe, 17 to 22 March 2023
Europe, 28 February to 4 March 2023

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Prague's worst days

DayUS AQIEpisode
7 Mar 2025 16575.6 µg/m³Germany, Poland and 25 more countries, March 2025
25 Jan 2026 15764.6 µg/m³Europe, January and February 2026
11 Jan 2024 15357.7 µg/m³Europe, 8 to 27 January 2024
9 Mar 2025 15155.7 µg/m³Germany, Poland and 25 more countries, March 2025
10 Mar 2025 14754.2 µg/m³Germany, Poland and 25 more countries, March 2025
23 Feb 2025 14754.1 µg/m³Europe, 14 February to 1 March 2025
24 Jan 2026 14754.1 µg/m³Europe, January and February 2026
31 Mar 2024 13950.9 µg/m³Europe, March and April 2024
10 Jan 2024 13248.1 µg/m³Europe, 8 to 27 January 2024
29 Dec 2024 13248.0 µg/m³Europe, 24 December 2024 to 3 January 2025

Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Prague, Czechia, 1 Jan 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/cz/prague/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Prague now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 20:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).