SmogRank / Czechia / Olomouc Region / Olomouc

Olomouc, month by month

Olomouc has a measured daily mean on 767 days since 1 January 2023. Its worst month was January 2024, at 84 US AQI (26.7 µg/m³), 152nd of 2,385 cities on that month's world ranking. Its cleanest was August 2025, at 52 US AQI (9.5 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)43 days measured
Jan10 daysFeb3 daysMar2 daysApr6 daysMay11 daysJun4 daysJulnoneAugnoneSep1 dayOct6 days
2025too few days for a mean (a year needs 256)165 days measured
Jan15 daysFeb16 daysMar12 daysApr20 daysMay13 daysJun3 daysJul9 daysAug52#1,350Sep18 daysOct9 daysNov10 daysDec15 days
2024too few days for a mean (a year needs 257)221 days measured
Jan84#152Feb63#323Mar15 daysApr54#907May52#832JunnoneJul54#576Aug1 daySepnoneOct11 daysNov72#197Dec73#237
202360 for the year338 days measured145th of 1,355 in the world
Jan60#285Feb70#148Mar63#76Apr60#190May56#279Jun58#509Jul21 daysAug54#463Sep61#195Oct58#150Nov55#375Dec75#127
Each square is a month's mean PM2.5 in US AQI from Olomouc'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 Olomouc 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 20266 of 12 days measured; a month needs 9. 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 202611 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Apr 20266 of 30 days measured; a month needs 21. The others: 24 with under 18 hours of readings or readings that failed our checks.
Mar 20262 of 31 days measured; a month needs 22. The others: 29 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 202610 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Dec 202515 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Nov 202510 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks.
Oct 20259 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Sep 202518 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jul 20259 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Jun 20253 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks.
May 202513 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Apr 202520 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Mar 202512 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Feb 202516 of 28 days measured; a month needs 20. The others: 12 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 2024No day measured. The others: 30 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.
Jul 202321 of 31 days measured; a month needs 22. The others: 10 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.

Olomouc's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2024 8426.7 µg/m³29 of 31152ndof 2,385Europe, 27 January to 2 February 2024
Europe, 28 to 31 January 2024and 1 more
December 2023 7521.9 µg/m³28 of 31127thof 2,247Europe, December 2023
Eastern Europe, November and December 2023
December 2024 7320.7 µg/m³24 of 31237thof 2,616Europe, 24 December 2024 to 3 January 2025
November 2024 7220.6 µg/m³27 of 30197thof 2,624Eastern Europe, 25 to 29 November 2024
Europe, November 2024and 1 more
February 2023 7019.3 µg/m³28 of 28148thof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
February 2024 6315.5 µg/m³29 of 29323rdof 2,486Europe, 27 January to 2 February 2024

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.

Olomouc's worst days

DayUS AQIEpisode
24 Jan 2026 184103.0 µg/m³Europe, January and February 2026
25 Jan 2026 16981.3 µg/m³Europe, January and February 2026
10 Jan 2024 16068.4 µg/m³Europe, 8 to 27 January 2024
11 Jan 2024 15865.1 µg/m³Europe, 8 to 27 January 2024
7 Dec 2023 15864.9 µg/m³Europe, December 2023
23 Jan 2026 15764.5 µg/m³Europe, January and February 2026
21 Jan 2024 15663.1 µg/m³Europe, 8 to 27 January 2024
4 Feb 2026 15662.2 µg/m³Europe, January and February 2026
15 Jan 2026 15459.4 µg/m³Europe, January and February 2026
30 Dec 2024 15256.4 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, Olomouc, Czechia, 1 Jan 2023 – 12 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/cz/olomouc/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.

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

Updated 2026-10-12 22:07 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).