SmogRank / Mexico / Guanajuato / Salamanca
Salamanca, month by month
Salamanca has a measured daily mean on 1,030 days since 10 January 2023. Its worst month was May 2023, at 90 US AQI (30.0 µg/m³), 62nd of 1,600 cities on that month's world ranking. Its cleanest was September 2025, at 56 US AQI (11.8 µg/m³). 2025 averaged 65 US AQI (16.5 µg/m³), against 74 US AQI (21.4 µg/m³) in 2023.
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
15 months
| Month | Why |
|---|---|
| Jun 2026 | 20 of 30 days measured; a month needs 21. The others: 10 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. |
| Jan 2026 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Aug 2025 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | 21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | 19 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | 1 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 5 of 31 days measured; a month needs 22. The others: 26 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. |
| Dec 2023 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 10 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | 2 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
| Jan 2023 | 13 of 31 days measured; a month needs 22. The others: 7 missing from OpenAQ's archive, 2 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.
Salamanca's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| May 2023 | 9030.0 µg/m³ | 62ndof 1,600 | Guanajuato and Jalisco, Mexico, May 2023 |
| June 2023 | 8426.6 µg/m³ | 150thof 1,603 | Southern Mexico, June 2023 |
| April 2024 | 8125.4 µg/m³ | 118thof 2,520 | – |
| April 2023 | 7622.5 µg/m³ | 92ndof 1,622 | – |
| November 2025 | 7522.2 µg/m³ | 350thof 2,715 | – |
| March 2024 | 7421.4 µg/m³ | 140thof 1,698 | – |
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.
Salamanca's worst days
| Day | US AQI | Episode |
|---|---|---|
| 1 Jan 2024 | 211136.0 µg/m³ | Southern Mexico, January 2024 |
| 3 May 2024 | 15966.7 µg/m³ | – |
| 23 Apr 2024 | 13448.7 µg/m³ | – |
| 18 May 2023 | 13247.9 µg/m³ | – |
| 19 Jan 2023 | 11842.6 µg/m³ | Southern Mexico, January 2023 |
| 5 May 2023 | 11842.6 µg/m³ | Guanajuato and Jalisco, Mexico, May 2023 |
| 25 May 2023 | 11742.2 µg/m³ | – |
| 18 Jun 2023 | 11239.8 µg/m³ | Southern Mexico, June 2023 |
| 4 May 2023 | 10838.5 µg/m³ | Guanajuato and Jalisco, Mexico, May 2023 |
| 10 Mar 2024 | 10838.2 µg/m³ | – |
Daily means, the highest since 10 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, Salamanca, Mexico, 10 Jan 2023 – 11 Oct 2026. Monitor data from Sinaica Mexico via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/mx/salamanca/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.
Salamanca 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).