SmogRank / World / Mexico / 2024
Most polluted cities in Mexico, 2024
3 cities in Mexico ranked by their average PM2.5 over the 366 days; 3 above the WHO annual guideline (5.0 µg/m³). Worst: Celaya at 24.1 µg/m³, #74 of 2,052 cities in the world. Cleanest: Heroica Matamoros at 11.0. A city needs measurements on 70% of the days to be ranked.
OpenAQ's archive, where our readings come from, has almost none for one of these days. Cities in the United States and Europe have it from the EPA's and the European Environment Agency's own records of the same monitors; elsewhere a city's average is over its other days. Why.
Mexico has 43 cities ranked over the last 30 days, but only 3 here: most of its monitors have no readings for 2024 in OpenAQ's archive, where ours come from, or too few to rank. Cities missing from this board weren't clean, just not measured.
Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.
- 1CelayaGuanajuato 11%
- 2Heroica MatamorosTamaulipas 3%
- 3NogalesSonora 2%
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
All cities in the world, 2024 · Mexico now
Regions
Ranked cities in each region, 2024.
Use this board
SmogRank, most polluted cities in Mexico, PM2.5, 2024, smogrank.com/mx/history/2024 (accessed 6 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.