SmogRank / Mexico / Guanajuato / San Miguel de Allende
San Miguel de Allende, month by month
San Miguel de Allende has a measured daily mean on 987 days since 1 January 2023. Its worst month was May 2024, at 77 US AQI (22.9 µg/m³), 110th of 2,684 cities on that month's world ranking. Its cleanest was June 2026, at 46 US AQI (8.2 µg/m³).
Every month since 2023
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
13 months
| Month | Why |
|---|---|
| May 2026 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Feb 2026 | 17 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Aug 2025 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | 20 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jul 2024 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jun 2024 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | 3 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | 7 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 11 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
| Jan 2023 | 18 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 7 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.
San Miguel de Allende's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| May 2024 | 7722.9 µg/m³ | 110thof 2,684 | – |
| May 2023 | 6918.7 µg/m³ | 113thof 1,600 | – |
| April 2025 | 6918.6 µg/m³ | 405thof 2,951 | – |
| May 2025 | 6717.5 µg/m³ | 329thof 2,826 | – |
| March 2025 | 6616.9 µg/m³ | 777thof 2,862 | Southern Mexico, March 2025 |
| April 2023 | 6516.6 µg/m³ | 144thof 1,622 | – |
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.
San Miguel de Allende's worst days
| Day | US AQI | Episode |
|---|---|---|
| 1 Jan 2026 | 13147.8 µg/m³ | Southern Mexico, January 2026 |
| 7 Jun 2024 | 11742.0 µg/m³ | Southern Mexico, June 2024 |
| 17 Nov 2025 | 10135.7 µg/m³ | – |
| 4 May 2023 | 9935.1 µg/m³ | – |
| 28 May 2024 | 9934.9 µg/m³ | – |
| 1 Jan 2024 | 9934.7 µg/m³ | Southern Mexico, January 2024 |
| 20 Mar 2025 | 9733.9 µg/m³ | Southern Mexico, March 2025 |
| 5 May 2023 | 9532.6 µg/m³ | – |
| 3 May 2023 | 9331.8 µg/m³ | – |
| 19 May 2024 | 9331.6 µg/m³ | – |
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, San Miguel de Allende, Mexico, 1 Jan 2023 – 11 Oct 2026. Monitor data from Sinaica Mexico via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/mx/san-miguel-de-allende/history (accessed 12 Oct 2026).
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.
San Miguel de Allende now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 23:07 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).