SmogRank / France / Pays de la Loire / La Roche-sur-Yon

La Roche-sur-Yon, month by month

La Roche-sur-Yon has a measured daily mean on 448 days since 11 January 2023. Its worst month was February 2023, at 62 US AQI (15.0 µg/m³), 342nd of 1,129 cities on that month's world ranking. Its cleanest was July 2023, at 28 US AQI (5.0 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)21 days measured
Jan4 daysFebnoneMarnoneAprnoneMay3 daysJun2 daysJul3 daysAugnoneSep3 daysOct6 days
2025too few days for a mean (a year needs 256)1 day measured
Jan1 dayFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)126 days measured
Jan61#515Feb48#932Mar15 daysApr32#1,774May29#2,222JunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
202349 for the year300 days measured688th of 1,355 in the world
Jan7 daysFeb62#342Mar58#130Apr45#803May46#885Jun48#1,008Jul28#1,232Aug15 daysSep19 daysOct32#1,587Nov52#717Dec51#894
Each square is a month's mean PM2.5 in US AQI from La Roche-sur-Yon'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 La Roche-sur-Yon marked; each year, the year's.
Good0–50
Moderate51–100
Unhealthy for 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 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 20263 of 30 days measured; a month needs 21. The others: 27 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 20263 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jun 20262 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
May 20263 of 31 days measured; a month needs 22. The others: 28 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 20264 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2025No day measured. The others: 31 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 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2025No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 20251 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
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.
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.
Sep 202319 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Aug 202315 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jan 20237 of 31 days measured; a month needs 22. The others: 14 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.

La Roche-sur-Yon's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2023 6215.0 µg/m³27 of 28342ndof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
January 2024 6114.3 µg/m³29 of 31515thof 2,385Europe, 8 to 27 January 2024
Western Europe, January 2024
March 2023 5812.9 µg/m³31 of 31130thof 911Europe, 4 to 7 March 2023
Europe, 28 February to 4 March 2023
November 2023 529.6 µg/m³30 of 30717thof 2,243France, Belgium and 2 more countries, November and December 2023
December 2023 519.2 µg/m³31 of 31894thof 2,247France, Belgium and 2 more countries, November and December 2023
June 2023 488.6 µg/m³30 of 301,008thof 1,603–

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.

La Roche-sur-Yon's worst days

DayUS AQIEpisode
3 Mar 2023 14252.3 µg/m³Europe, 28 February to 4 March 2023
9 Feb 2023 13950.9 µg/m³Europe, 6 to 25 February 2023
14 Jan 2024 11440.8 µg/m³Europe, 8 to 27 January 2024
Western Europe, January 2024
10 Feb 2023 10537.2 µg/m³Europe, 6 to 25 February 2023
4 Mar 2023 10235.8 µg/m³Europe, 4 to 7 March 2023
Europe, 28 February to 4 March 2023
2 Mar 2023 9934.6 µg/m³Europe, 28 February to 4 March 2023
13 Jan 2024 9432.1 µg/m³Europe, 8 to 27 January 2024
13 Feb 2023 9331.6 µg/m³Europe, 6 to 25 February 2023
22 Jan 2023 8929.4 µg/m³France, The Netherlands and United Kingdom, January 2023
2 Dec 2023 8829.0 µg/m³France, Belgium and 2 more countries, November and December 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, La Roche-sur-Yon, France, 11 Jan 2023 – 12 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/fr/la-roche-sur-yon/history (accessed 13 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.

La Roche-sur-Yon now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-13 05:07 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).