New Mexico Air Quality Rankings
County-level AQI rollup using EPA Air Quality System monitor records. Refreshed as new EPA AQS data lands.
County-by-county air quality data for New Mexico based on EPA AQS annual AQI readings. Data covers 16 monitored counties for 2024.
New Mexico (2024): 16 counties monitored. State average median AQI: 37 (national average: 38.8). 75% of monitored days rated "Good." Most unhealthy air: Dona Ana County (13 days above AQI 100).
New Mexico air quality on this page is drawn from the EPA Air Quality System (AQS), which aggregates daily readings from federal, state, tribal, and local monitors into annual summaries per county for 2024, the current dataset's reporting year (county coverage and the state/national average shown above).
The heaviest burden of unhealthy days lands on Dona Ana County (13 days above AQI 100), while Los Alamos County records the cleanest air with a median AQI of 14.
AQI values translate ambient concentrations of pollutants (ozone, PM2.5, PM10, NO₂, SO₂, CO) onto a single 0–500 scale with six health-based bands. A low median AQI reflects typical daily conditions; peak values matter separately because short-term exposure drives most acute health effects. Counties without monitors are not "clean" - they are simply unmeasured by EPA AQS. For site-specific exposure guidance, check AirNow.gov alongside the county detail links below.
Which New Mexico counties have the worst air quality?
Ranked by median AQI (higher = worse). Click a county for full environmental data.
Frequently Asked Questions
What is the air quality like in New Mexico?
In 2024, New Mexico had an average median AQI of 37 across 16 monitored counties, with 75% of monitored days rated "Good" (AQI 0–50). The national average median AQI is 38.8.
Which county in New Mexico has the worst air quality?
Based on 2024 EPA AQS data, Dona Ana County had the most unhealthy air days in New Mexico - 13 days above AQI 100, with a median AQI of 62.
About This Data
Air quality data is from the EPA Air Quality System (AQS), Annual AQI by County dataset. Counties with fewer than 10 monitored days are excluded. "Unhealthy days" counts days with AQI above 100 (Unhealthy for Sensitive Groups or worse). All data is for 2024.
Source: U.S. Environmental Protection Agency, Air Quality System (AQS)
Read our methodology - how this data is sourced, computed, and verified.