Montana(MT)
Air quality overview and monitoring data — 2025
708
Monitoring Sites
4,941
Active Monitors
44
Counties with Data
61
Cities Monitored
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County Air Quality
| County | Median AQI ▲ | 90th %ile | Max AQI | Good | Moderate | USG | Unhealthy |
|---|---|---|---|---|---|---|---|
| Lake | 4 | 9 | 9 | 20 | 0 | 0 | 0 |
| Rosebud | 4 | 17 | 21 | 18 | 0 | 0 | 0 |
| Powell | 6 | 20 | 21 | 17 | 0 | 0 | 0 |
| Roosevelt | 9 | 31 | 38 | 17 | 0 | 0 | 0 |
| Beaverhead | 12 | 23 | 48 | 175 | 0 | 0 | 0 |
| Hill | 13 | 34 | 157 | 141 | 7 | 0 | 1 |
| Sheridan | 13 | 30 | 31 | 19 | 0 | 0 | 0 |
| Dawson | 14 | 30 | 162 | 172 | 8 | 0 | 1 |
| Gallatin | 14 | 25 | 62 | 224 | 2 | 0 | 0 |
| Teton | 14 | 26 | 89 | 169 | 4 | 0 | 0 |
| Sanders | 15 | 21 | 31 | 181 | 0 | 0 | 0 |
| Phillips | 18 | 41 | 168 | 161 | 8 | 1 | 1 |
| Ravalli | 19 | 56 | 80 | 142 | 32 | 0 | 0 |
| Glacier | 22 | 36 | 117 | 161 | 5 | 1 | 0 |
| Silver Bow | 27 | 54 | 77 | 150 | 31 | 0 | 0 |
| Missoula | 38 | 56 | 82 | 151 | 30 | 0 | 0 |
| Custer | 39 | 49 | 95 | 165 | 16 | 0 | 0 |
| Richland | 39 | 53 | 165 | 157 | 21 | 2 | 1 |
| Yellowstone | 39 | 52 | 85 | 157 | 24 | 0 | 0 |
| Flathead | 40 | 59 | 80 | 183 | 40 | 0 | 0 |
| Fergus | 44 | 49 | 87 | 166 | 14 | 0 | 0 |
| Lewis and Clark | 45 | 69 | 93 | 119 | 63 | 0 | 0 |
| Lincoln | 45 | 67 | 92 | 96 | 80 | 0 | 0 |
Pollutant Trends
Ozone
No data available
PM2.5
No data available
PM10
No data available
CO
No data available
NO2
No data available
SO2
No data available