SmogRank / France / Bourgogne-Franche-Comté / Besançon

Besançon, month by month

Besançon has a measured daily mean on 399 days since 11 January 2023. Its worst month was February 2023, at 63 US AQI (15.7 µg/m³), 298th of 1,129 cities on that month's world ranking. Its cleanest was August 2023, at 23 US AQI (4.1 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)10 days measured
Jan3 daysFebnoneMarnoneAprnoneMay2 daysJunnoneJulnoneAugnoneSep1 dayOct4 days
2025too few days for a mean (a year needs 256)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)68 days measured
Jan60#538Feb38#1,499Mar10 daysApr2 daysMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
202339 for the year321 days measured1,045th of 1,355 in the world
Jan9 daysFeb63#298Mar54#219Apr33#1,221May43#975Jun40#1,199Jul23#1,322Aug23#1,911Sep28#1,982Oct30#1,662Nov31#1,857Dec39#1,520
Each square is a month's mean PM2.5 in US AQI from Besançon'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 Besançon 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

33 months
MonthWhy
Oct 20264 of 12 days measured; a month needs 9. The others: 7 with readings for part of the day (a day needs 18 hours), 1 with under 18 hours of readings or readings that failed our checks.
Sep 20261 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 28 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 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 20262 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 20263 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured.
Nov 2025No day measured.
Oct 2025No day measured.
Sep 2025No day measured.
Aug 2025No day measured.
Jul 2025No day measured.
Jun 2025No day measured.
May 2025No day measured.
Apr 2025No day measured.
Mar 2025No day measured.
Feb 2025No day measured.
Jan 2025No day measured.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2024No day measured. The others: 31 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 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2024No day measured. The others: 31 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.
May 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 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 202410 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Jan 20239 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 11 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.

Besançon's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2023 6315.7 µg/m³28 of 28298thof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
January 2024 6014.0 µg/m³29 of 31538thof 2,385Europe, 8 to 27 January 2024
Western Europe, January 2024
March 2023 5410.6 µg/m³29 of 31219thof 911Europe, 4 to 7 March 2023
Europe, 28 February to 4 March 2023
May 2023 437.8 µg/m³28 of 31975thof 1,600–
June 2023 407.2 µg/m³30 of 301,199thof 1,603–
December 2023 397.1 µg/m³31 of 311,520thof 2,247–

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.

Besançon's worst days

DayUS AQIEpisode
3 Mar 2023 11541.2 µg/m³Europe, 28 February to 4 March 2023
11 Feb 2023 10838.5 µg/m³Europe, 6 to 25 February 2023
10 Feb 2023 10537.3 µg/m³Europe, 6 to 25 February 2023
12 Jan 2024 10436.6 µg/m³Europe, 8 to 27 January 2024
13 Jan 2024 10336.5 µg/m³Europe, 8 to 27 January 2024
4 Mar 2023 9734.0 µg/m³Europe, 4 to 7 March 2023
Europe, 28 February to 4 March 2023
2 Mar 2023 9532.8 µg/m³Europe, 28 February to 4 March 2023
13 Feb 2023 9130.6 µg/m³Europe, 6 to 25 February 2023
9 Feb 2023 8929.7 µg/m³Europe, 6 to 25 February 2023
12 Feb 2023 8828.9 µg/m³Europe, 6 to 25 February 2023

Daily means, the highest since 11 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, Besançon, France, 11 Jan 2023 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/fr/besancon/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.

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

Updated 2026-10-12 21:07 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).