SmogRank / Czechia / Central Bohemia / Mladá Boleslav

Mladá Boleslav, month by month

Mladá Boleslav has a measured daily mean on 713 days since 1 January 2023. Its worst month was January 2024, at 69 US AQI (18.8 µg/m³), 311th of 2,385 cities on that month's world ranking. Its cleanest was April 2024, at 49 US AQI (8.8 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)35 days measured
Jan7 daysFeb3 daysMar1 dayApr4 daysMay10 daysJun4 daysJulnoneAugnoneSep1 dayOct5 days
2025too few days for a mean (a year needs 256)126 days measured
Jan14 daysFeb15 daysMar10 daysApr12 daysMay10 daysJunnoneJul7 daysAug16 daysSep16 daysOct8 daysNov8 daysDec10 days
2024too few days for a mean (a year needs 257)215 days measured
Jan69#311Feb56#484Mar14 daysApr49#1,195May49#1,022JunnoneJul52#766Aug1 daySepnoneOct8 daysNov65#356Dec62#482
202357 for the year337 days measured199th of 1,355 in the world
Jan62#244Feb67#212Mar58#136Apr55#314May55#346Jun56#581Jul50#763Aug52#636Sep56#368Oct54#260Nov52#696Dec66#226
Each square is a month's mean PM2.5 in US AQI from Mladá Boleslav'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 Mladá Boleslav 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

27 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 2026No day measured. The others: 31 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 20264 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks.
May 202610 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Apr 20264 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks.
Mar 20261 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Feb 20263 of 28 days measured; a month needs 20. The others: 25 with under 18 hours of readings or readings that failed our checks.
Jan 20267 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks.
Dec 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Nov 20258 of 30 days measured; a month needs 21. The others: 22 with under 18 hours of readings or readings that failed our checks.
Oct 20258 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks.
Sep 202516 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Aug 202516 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Jul 20257 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks.
Jun 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Apr 202512 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Mar 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Feb 202515 of 28 days measured; a month needs 20. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jan 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Oct 20248 of 31 days measured; a month needs 22. The others: 23 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 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 202414 of 31 days measured; a month needs 22. The others: 17 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.

Mladá Boleslav's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2024 6918.8 µg/m³30 of 31311thof 2,385Europe, 27 January to 2 February 2024
Europe, 8 to 27 January 2024
February 2023 6717.6 µg/m³27 of 28212thof 1,129Europe, 6 to 25 February 2023
December 2023 6617.2 µg/m³28 of 31226thof 2,247Eastern Europe, December 2023
Europe, December 2023and 1 more
November 2024 6516.4 µg/m³26 of 30356thof 2,624Eastern Europe, 25 to 29 November 2024
Europe, November 2024and 1 more
January 2023 6215.0 µg/m³25 of 31244thof 1,261Poland and Czechia, January 2023
Eastern Europe, January 2023
December 2024 6214.9 µg/m³24 of 31482ndof 2,616Europe, 24 December 2024 to 3 January 2025

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.

Mladá Boleslav's worst days

DayUS AQIEpisode
24 Jan 2026 16575.8 µg/m³Europe, January and February 2026
1 Jan 2023 15864.9 µg/m³Eastern Europe, January 2023
16 Feb 2023 13449.1 µg/m³Europe, 6 to 25 February 2023
23 Jan 2026 13248.0 µg/m³Europe, January and February 2026
4 Feb 2025 12545.2 µg/m³Europe, 1 to 14 February 2025
7 Feb 2023 12244.2 µg/m³Europe, 6 to 25 February 2023
31 Jan 2024 12243.9 µg/m³Europe, 27 January to 2 February 2024
10 Nov 2024 12143.6 µg/m³Europe, November 2024
5 Mar 2025 11942.9 µg/m³Germany, Poland and 25 more countries, March 2025
21 Jan 2024 11842.6 µg/m³Europe, 8 to 27 January 2024

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, Mladá Boleslav, 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/mlada-boleslav/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.

Mladá Boleslav 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).