Missoula, Montana Air Quality
Missoula County, Montana (MT)
↓ Improvingover 10 years
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days). This area has seen measurable air quality improvement over the decade.
Air Quality Day Breakdown
Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).
Year-by-Year Data
| Year | Median AQI | 90th Pct | Max AQI | Good Days | Moderate | Unhealthy+ | Pollutant |
|---|---|---|---|---|---|---|---|
| 2023 | 53 | 76 | 134 | 156 | 200 | 8 | PM2.5 |
| 2022 | 54 | 81 | 190 | 149 | 201 | 15 | PM2.5 |
| 2021 | 56 | 94 | 162 | 122 | 213 | 30 | PM2.5 |
| 2020 | 54 | 85 | 185 | 155 | 192 | 19 | PM2.5 |
| 2019 | 52 | 78 | 153 | 173 | 188 | 4 | PM2.5 |
| 2018 | 54 | 80 | 154 | 146 | 215 | 4 | PM2.5 |
| 2017 | 65 | 185 | 1130 | 52 | 240 | 73 | PM2.5 |
| 2016 | 58 | 96 | 139 | 72 | 269 | 25 | PM2.5 |
| 2015 | 56 | 92 | 209 | 126 | 216 | 23 | PM2.5 |
| 2014 | 52 | 87 | 159 | 173 | 174 | 18 | PM2.5 |
What This Means for Missoula County Residents
Missoula, Montana has received an Air Quality Grade of C (54/100) based on a decade of EPA monitoring data. The current median AQI of 53 falls in the "Moderate" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 1 points over the monitoring period. This trend suggests continued investment in emission controls and cleaner energy.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 15 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.