SmogRank / Czechia / Liberec Region / Liberec

Liberec, month by month

Liberec has a measured daily mean on 736 days since 1 January 2023. Its worst month was January 2024, at 63 US AQI (15.5 µg/m³), 433rd of 2,385 cities on that month's world ranking. Its cleanest was May 2024, at 42 US AQI (7.6 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)38 days measured
Jan10 daysFeb3 daysMar2 daysApr3 daysMay10 daysJun4 daysJulnoneAugnoneSep1 dayOct5 days
2025too few days for a mean (a year needs 256)144 days measured
Jan15 daysFeb16 daysMar11 daysApr16 daysMay11 daysJun1 dayJul7 daysAug16 daysSep18 daysOct8 daysNov11 daysDec14 days
2024too few days for a mean (a year needs 257)215 days measured
Jan63#433Feb49#866Mar15 daysApr47#1,248May42#1,482JunnoneJul48#1,103Aug1 daySepnoneOct7 daysNov59#478Dec55#735
202355 for the year339 days measured310th of 1,355 in the world
Jan55#399Feb61#380Mar55#181Apr57#250May56#297Jun55#603Jul52#714Aug52#668Sep54#451Oct52#366Nov49#889Dec59#348
Each square is a month's mean PM2.5 in US AQI from Liberec'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 Liberec 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 20263 of 30 days measured; a month needs 21. The others: 27 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 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Nov 202511 of 30 days measured; a month needs 21. The others: 19 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 202518 of 30 days measured; a month needs 21. The others: 12 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 20251 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
May 202511 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Apr 202516 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Mar 202511 of 31 days measured; a month needs 22. The others: 20 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 20247 of 31 days measured; a month needs 22. The others: 24 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.

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

Liberec's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2024 6315.5 µg/m³27 of 31433rdof 2,385Europe, 27 January to 2 February 2024
Europe, 8 to 27 January 2024
February 2023 6114.6 µg/m³28 of 28380thof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
November 2024 5913.6 µg/m³27 of 30478thof 2,624Europe, November 2024
December 2023 5913.2 µg/m³28 of 31348thof 2,247Europe, December 2023
Eastern Europe, November and December 2023
April 2023 5712.3 µg/m³29 of 30250thof 1,622Europe, April 2023
May 2023 5611.6 µg/m³27 of 31297thof 1,600Czechia and Germany, May 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.

Liberec's worst days

DayUS AQIEpisode
24 Jan 2026 17489.0 µg/m³Europe, January and February 2026
25 Jan 2026 14051.2 µg/m³Europe, January and February 2026
9 Jan 2024 13950.9 µg/m³Europe, 8 to 27 January 2024
23 Jan 2026 12645.7 µg/m³Europe, January and February 2026
16 Feb 2023 11340.4 µg/m³Europe, 6 to 25 February 2023
11 Nov 2024 10838.3 µg/m³Europe, November 2024
14 Feb 2025 10738.0 µg/m³Europe, 14 February to 1 March 2025
Europe, 1 to 14 February 2025
24 Mar 2025 10436.9 µg/m³Europe, March 2025
1 Dec 2023 10336.4 µg/m³Eastern Europe, November and December 2023
2 Mar 2023 10236.1 µg/m³Europe, 28 February to 4 March 2023

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, Liberec, 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/liberec/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.

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

Updated 2026-10-12 18:07 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).