SmogRank / World / North America / Mexico / Baja California
Most polluted cities in Baja California, Mexico
2 measured cities, last 30 days; 2 above the WHO 24-hour guideline. Worst: Mexicali at 23.9 µg/m³, #188 in the world.
About 68.8K people in this city breathed unhealthy air on an average day over the last 30 days.
Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.
Cities coloured by their PM2.5 over the last 24 hours. Fires, smoke and ash: Oct 5, the newest UTC day mapped.
- 1Mexicali 68.8K
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
Baja California 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 |
|---|---|
| Ensenada | ≈ 9 µg/m³ |
| Rosarito | ≈ 14 µg/m³ |
| Tecate | ≈ 11 µg/m³ |
| Pórticos de San Antonio | ≈ 14 µg/m³ |
| Santa Isabel | ≈ 5 µg/m³ |
| La Joya | ≈ 14 µg/m³ |
| Rodolfo Sánchez Taboada | ≈ 6 µg/m³ |
| Terrazas del Valle | ≈ 10 µg/m³ |
| Villa del Prado 2da Sección | ≈ 10 µg/m³ |
| Ciudad Guadalupe Victoria | ≈ 6 µg/m³ |
| San Felipe | ≈ 4 µg/m³ |
| Lázaro Cárdenas | ≈ 6 µg/m³ |
| Las Delicias | ≈ 10 µg/m³ |
| Puebla | ≈ 5 µg/m³ |
Bad-air episodes in Baja California
- Western United States and Mexico, December 202513 to 22 December 2025, 10 days27 cities172 µg/m³peak, Tijuana
- South-western United States and Mexico, December 2024 to January 202529 December 2024 to 2 January 2025, 5 days37 cities167 µg/m³peak, Phoenix
- Western United States and Mexico, December 202324 to 28 December 2023, 5 days32 cities83 µg/m³peak, Tijuana
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 Baja California, Mexico, PM2.5, last 30 days to 7 Oct 2026, 01:00 UTC, smogrank.com/mx/region/baja-california?w=30d.
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 2026-10-07 01:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.