Bad Air Days in Lea County, New Mexico: 4 a Year
4 bad air days a year
About the middle of monitored US counties. Ranked 261 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (26% particle days).
Which months to watch
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in June and July and August. Averaged over 2016 to 2025.
What actually helps here
- Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.
The record for Lea
In 2000 to 2009 this county averaged 3 bad days a year; in 2016 to 2025, 4. Not much has changed. The worst recent year was 2025, with 8 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2025-04-18 | 193 | PM2.5 |
| 2025-03-18 | 186 | PM2.5 |
| 2025-03-03 | 166 | PM2.5 |
| 2025-03-14 | 161 | PM2.5 |
| 2025-04-01 | 158 | PM2.5 |
An ordinary day in Lea
Across 3,648 monitored days from 2016 to 2025, the air in Lea County rated Good on 67% of them, less often than the 72% typical of monitored counties, and Moderate on 32%. The median day sat at AQI 45; one day in ten went above 68.
The pollutant setting the AQI on an ordinary day here:
- ozone73%2,660 days
- fine particles (PM2.5)26%954 days
- nitrogen dioxide1%34 days
Year by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 251 | 106 | 8 | 5 | 44 | 193 |
| 2024 | 364 | 255 | 104 | 5 | 0 | 44 | 150 |
| 2023 | 364 | 235 | 122 | 7 | 0 | 45 | 133 |
| 2022 | 365 | 237 | 123 | 5 | 0 | 44 | 126 |
| 2021 | 365 | 257 | 105 | 3 | 1 | 44 | 151 |
| 2020 | 366 | 310 | 56 | 0 | 0 | 40 | 79 |
| 2019 | 365 | 210 | 151 | 4 | 0 | 48 | 140 |
| 2018 | 365 | 193 | 166 | 6 | 0 | 50 | 143 |
| 2017 | 365 | 184 | 177 | 4 | 0 | 50 | 133 |
| 2016 | 364 | 305 | 59 | 0 | 0 | 42 | 97 |
| 2015 | 361 | 278 | 82 | 1 | 1 | 41 | 159 |
| 2014 | 360 | 250 | 107 | 3 | 0 | 44 | 113 |
| 2013 | 365 | 254 | 109 | 2 | 0 | 42 | 111 |
| 2012 | 363 | 280 | 82 | 1 | 0 | 41 | 117 |
| 2011 | 360 | 225 | 128 | 7 | 0 | 46 | 120 |
| 2010 | 365 | 326 | 39 | 0 | 0 | 37 | 68 |
*2025 may be a partial year in EPA's file.
New Mexico compared
- Dona Ana County28/yr
- Eddy County19/yr
- Bernalillo County15/yr
- San Juan County6/yr
- Luna County5/yr
- Sandoval County2/yr
- Valencia County1/yr
- Rio Arriba County1/yr
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day, and on why a purifier does not touch ozone in smoke vs ozone.