SmogRank / France / Pays de la Loire / Saint-Nazaire

Saint-Nazaire, month by month

Saint-Nazaire has a measured daily mean on 294 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 May 2024, at 31 US AQI (5.5 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)22 days measured
Jan4 daysFebnoneMarnoneAprnoneMay3 daysJun2 daysJul4 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)56 days measured
JannoneFeb1 dayMarnoneApr35#1,600May31#2,156JunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)215 days measured
Jan8 daysFeb62#342Mar49#362Apr40#1,001May35#1,249Jun41#1,188Jul20 daysAug12 daysSep17 daysOct14 daysNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Saint-Nazaire'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 Saint-Nazaire 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

39 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: 20 with readings for part of the day (a day needs 18 hours), 7 with under 18 hours of readings or readings that failed our checks.
Aug 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 20264 of 31 days measured; a month needs 22. The others: 27 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 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 20241 of 29 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 202314 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Sep 202317 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Aug 202312 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jul 202320 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jan 20238 of 31 days measured; a month needs 22. The others: 13 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.

Saint-Nazaire's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2023 6215.0 µg/m³26 of 28342ndof 1,129Europe, 28 February to 4 March 2023
Europe, 6 to 25 February 2023
March 2023 498.9 µg/m³31 of 31362ndof 911Europe, 28 February to 4 March 2023
June 2023 417.3 µg/m³30 of 301,188thof 1,603–
April 2023 407.2 µg/m³26 of 301,001stof 1,622–
May 2023 356.3 µg/m³31 of 311,249thof 1,600–
April 2024 356.3 µg/m³29 of 301,600thof 2,520–

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.

Saint-Nazaire's worst days

DayUS AQIEpisode
9 Feb 2023 11139.5 µg/m³Europe, 6 to 25 February 2023
14 Feb 2023 9432.0 µg/m³Europe, 6 to 25 February 2023
9 Oct 2023 9331.5 µg/m³–
3 Mar 2023 9130.7 µg/m³Europe, 28 February to 4 March 2023
10 Feb 2023 9029.9 µg/m³Europe, 6 to 25 February 2023
12 Feb 2023 8828.9 µg/m³Europe, 6 to 25 February 2023
8 Feb 2023 8527.4 µg/m³Europe, 6 to 25 February 2023
11 Feb 2023 8326.5 µg/m³Europe, 6 to 25 February 2023
6 Sept 2023 8326.4 µg/m³–
2 Mar 2023 8326.3 µg/m³Europe, 28 February to 4 March 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, Saint-Nazaire, 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/saint-nazaire/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.

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

Updated 2026-10-13 02:07 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).