Air Quality Rankings for Country Of Mexico (2026)
Country Of Mexico has 2 cities tracked by EPA air-quality monitors, with a state-wide 5-year median AQI of 62 — 21 points more polluted than the national average of AQI 41. SONORA, Country Of Mexico ranks #1 with the cleanest air (AQI 44, Grade D), while BAJA CALIFORNIA NORTE, Country Of Mexico sits at the bottom (AQI 81, Grade F).
How Country Of Mexico Compares
Country Of Mexico has 2 cities tracked by EPA air-quality monitors, with a state-wide 5-year median AQI of 62 — 21 points more polluted than the national average of AQI 41. SONORA, Country Of Mexico ranks #1 with the cleanest air (AQI 44, Grade D), while BAJA CALIFORNIA NORTE, Country Of Mexico sits at the bottom (AQI 81, Grade F). The rankings below are computed from the EPA Air Quality System (AQS), which aggregates daily AQI readings from federally certified monitors into annual averages. Cities are sorted by 5-year median AQI (lowest = cleanest = #1). The 5-year window smooths out year-to-year volatility from weather and wildfire events.
Country Of Mexico is bucking the national trend of broad improvement: 2 of 2 monitored cities show measurably worse air over the past decade, more than the 0 that are improving. Across western states this usually traces back to expanding wildfire smoke exposure; elsewhere it can reflect rising local emissions from population or freight growth.
The dominant pollutant across 1 of 2 Country Of Mexico cities is Ground-Level Ozone. Ground-level ozone forms when sunlight reacts with vehicle and industrial emissions. It is worst on hot, sunny, stagnant summer days and is the leading air quality concern across much of the Sun Belt and California. Other Country Of Mexico cities report Fine Particulate Matter (PM2.5) (1) as their dominant concern.
The city with the steepest decline is SONORA, Country Of Mexico, where median AQI is rising by 2.3 points per year. Rapid deterioration in a single city usually points to either wildfire-smoke exposure (in the West) or a new local emissions source — a power plant, port, or freight corridor coming online.
Full Country Of Mexico Ranking
| # | City | 5yr Avg AQI | Current AQI | Worst Pollutant | Trend | Grade |
|---|---|---|---|---|---|---|
| 1 | SONORA, Country Of Mexico | 44 | 53 | Ozone | Worsening | D |
| 2 | BAJA CALIFORNIA NORTE, Country Of Mexico | 81 | 66 | PM2.5 | Worsening | F |
Air quality data for Country Of Mexico is sourced from the EPA Air Quality System (AQS), which monitors outdoor air quality at thousands of stations nationwide.
Frequently Asked Questions
SONORA, Country Of Mexico has the best air quality in Country Of Mexico with a 5-year average AQI of 44 and a Grade D (47/100). Its dominant pollutant is Ground-Level Ozone and the long-run trend is worsening.
BAJA CALIFORNIA NORTE, Country Of Mexico has the worst air quality in Country Of Mexico with a 5-year average AQI of 81 and a Grade F (16/100). Its dominant pollutant is Fine Particulate Matter (PM2.5).
Country Of Mexico has 2 cities with EPA air quality monitoring data, covering 2014-2023 of daily AQI measurements aggregated into annual averages.
Country Of Mexico's state-wide 5-year median AQI is 62, 21 points more polluted than the national average of AQI 41. Country Of Mexico is bucking the national trend of broad improvement: 2 of 2 monitored cities show measurably worse air over the past decade, more than the 0 that are improving. Across western states this usually traces back to expanding wildfire smoke exposure; elsewhere it can reflect rising local emissions from population or freight growth.
Ground-Level Ozone is the dominant pollutant in 1 of 2 monitored Country Of Mexico cities. Ground-level ozone forms when sunlight reacts with vehicle and industrial emissions. It is worst on hot, sunny, stagnant summer days and is the leading air quality concern across much of the Sun Belt and California.
Country Of Mexico cities log an average of 20 days per year at "Unhealthy for Sensitive Groups" or worse, based on EPA monitor data over the last five years. Across all 2 Country Of Mexico cities tracked, that totals 198 unhealthy days over the period.
Cities ranked by 5-year average AQI (lower is better). Grades factor in average AQI, trend direction, unhealthy days, and dominant pollutant.
The this entity category groups every U.S. air quality and pollution monitoring entity sharing this attribute. The list above is the data; the paragraphs below explain what the grouping means against the broader the EPA Air Quality System (AQS) distribution and how to read the relative rankings within the category.
For readers using this category as a starting point, the per-entity detail pages linked from the table above carry the underlying the EPA Air Quality System (AQS) data in full. The category-level view is the filter; the per-entity pages are the actual answer.
Source: EPA Outdoor Air Quality Data, 2026.