SmogRank / World / North America / Mexico / Sonora
Most polluted cities in Sonora, Mexico
1 measured city, last 24 hours; 0 above the WHO 24-hour guideline. The only one: Nogales at 8.3 µg/m³, #665 in the world.
Cities coloured by their PM2.5 over the last 24 hours. Fires, smoke and ash: Oct 5, the newest UTC day mapped.
- 1Nogales 460.6×▲41
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
Estimated: cities without a monitor
Sonora cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Hermosillo | ≈ 4 µg/m³ |
| Ciudad Obregón | ≈ 7 µg/m³ |
| San Luis Río Colorado | ≈ 6 µg/m³ |
| Heroica Guaymas | ≈ 4 µg/m³ |
| Navojoa | ≈ 7 µg/m³ |
| Agua Prieta | ≈ 3 µg/m³ |
| Puerto Peñasco | ≈ 5 µg/m³ |
| Heroica Caborca | ≈ 5 µg/m³ |
| Empalme | ≈ 4 µg/m³ |
| Esperanza | ≈ 7 µg/m³ |
| Cananea | ≈ 3 µg/m³ |
| Miguel Alemán (La Doce) | ≈ 4 µg/m³ |
| Huatabampo | ≈ 8 µg/m³ |
| Magdalena de Kino | ≈ 3 µg/m³ |
Bad-air episodes in Sonora
- Western United States and Mexico, January and February 202529 January to 2 February 2025, 5 days31 cities38 µg/m³peak, Woodburn
- South-western United States and Mexico, December 2024 to January 202529 December 2024 to 2 January 2025, 5 days37 cities167 µg/m³peak, Phoenix
Times when many cities around here had PM2.5 at twice their usual or more on the same days.
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SmogRank, most polluted cities in Sonora, Mexico, PM2.5, last 24 hours to 6 Oct 2026, 23:00 UTC, smogrank.com/mx/region/sonora.
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.
Updated 2026-10-06 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.