Missoula, Montana Air Quality
Missoula County, Montana (MT)
↓ Improvingover 10 years
How Missoula, Montana Air Quality Compares
Missoula, Montana's median AQI of 53is 29% worse than the national average of 41. Residents experience an average of 15 unhealthy air days per year, above the national threshold for concern. The primary pollutant of concern is Fine Particulate Matter (PM2.5).
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 monitoring data from the EPA's air quality monitoring program. 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. The American Lung Association's State of the Air report provides additional context on long-term health risks from air pollution exposure.
Related Cities in Montana
Frequently Asked Questions
Missoula, Montana has a current median AQI of 53, which falls in the "Moderate" range. The area has received an Air Quality Grade of C (54/100) based on 10 years of EPA monitoring data.
Air quality in Missoula, Montana is improving over the past decade. The median AQI has changed by +1 points from 2014 to 2023.
Missoula, Montana averages 15 unhealthy air quality days per year over the past 5 years. On these days, sensitive groups including children, the elderly, and those with respiratory conditions should limit outdoor activity.
The primary pollutant affecting Missoula, Montana is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the Missoula County area.
Missoula, Montana averages 15 unhealthy air days per year. Asthma patients should monitor daily AQI readings and limit outdoor activity when AQI exceeds 100. The primary pollutant is Fine Particulate Matter (PM2.5), which is a known asthma trigger.
With a median AQI of 53 (Moderate), outdoor exercise in Missoula, Montana is safe most days, though sensitive individuals should check daily AQI before intense workouts. Missoula, Montana averages 15 days per year when athletes should move workouts indoors.
this entity is one of the data points covered by this site’s U.S. air quality and pollution monitoring dataset. The detail above comes directly from the EPA Air Quality System (AQS); the context that follows situates the headline numbers against the broader distribution across U.S. counties and states.
Every number on this page links back to the EPA Air Quality System (AQS); the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. counties and states with similar size, similar exposure, or similar geography — not the national-level summary alone.