Bad Air Days in Yuma County, Arizona: 9 a Year
9 bad air days a year
More bad air days than three quarters of monitored counties. Ranked 100 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (68% particle days).
When the bad days come in Yuma
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in June and July. Averaged over 2016 to 2025.
What actually helps here
- Particles (wildfire smoke, dust) cause enough bad days here to matter. A HEPA purifier sized to your bedroom removes them; run it with windows shut on bad days.
- Upgrade the furnace or AC filter to MERV 13 so the whole house is filtered, not just one room.
Better or worse than it was
In 2000 to 2009 this county averaged 14 bad days a year; in 2016 to 2025, 9. The air has improved. The worst recent year was 2018, with 16 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2023-08-20 | 519 | PM10 |
| 2016-12-16 | 410 | PM10 |
| 2020-10-26 | 319 | PM10 |
| 2017-02-17 | 235 | PM10 |
| 2025-01-08 | 211 | PM10 |
Most days, not the worst ones
Across 3,652 monitored days from 2016 to 2025, the air in Yuma County rated Good on 56% of them, less often than the 72% typical of monitored counties, and Moderate on 41%. The median day sat at AQI 48; one day in ten went above 73.
The pollutant setting the AQI on an ordinary day here:
- ozone52%1,912 days
- fine particles (PM2.5)30%1,081 days
- coarse dust (PM10)18%659 days
Year by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 197 | 161 | 7 | 1 | 48 | 211 |
| 2024 | 365 | 212 | 149 | 4 | 1 | 47 | 179 |
| 2023 | 365 | 204 | 150 | 11 | 5 | 48 | 519 |
| 2022 | 365 | 228 | 128 | 9 | 0 | 46 | 142 |
| 2021 | 365 | 186 | 173 | 6 | 1 | 50 | 170 |
| 2020 | 366 | 206 | 157 | 3 | 1 | 49 | 319 |
| 2019 | 365 | 226 | 136 | 3 | 0 | 47 | 129 |
| 2018 | 365 | 202 | 147 | 16 | 1 | 49 | 169 |
| 2017 | 365 | 201 | 150 | 14 | 2 | 49 | 235 |
| 2016 | 366 | 199 | 153 | 14 | 2 | 49 | 410 |
| 2015 | 365 | 252 | 99 | 14 | 1 | 44 | 266 |
| 2014 | 365 | 204 | 144 | 17 | 5 | 49 | 284 |
| 2013 | 365 | 231 | 124 | 10 | 1 | 45 | 540 |
| 2012 | 366 | 224 | 116 | 26 | 2 | 47 | 166 |
| 2011 | 363 | 251 | 98 | 14 | 0 | 41 | 140 |
| 2010 | 358 | 259 | 91 | 8 | 0 | 41 | 147 |
*2025 may be a partial year in EPA's file.
Arizona compared
- Maricopa County89/yr
- Pinal County53/yr
- Gila County14/yr
- Pima County9/yr
- Santa Cruz County3/yr
- Cochise County3/yr
- La Paz County2/yr
- Coconino County2/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.