Deer Lodge, Montana Air Quality

Deer Lodge air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now

Deer Lodge, MT · Air quality right now

The air quality index in Deer Lodge, MT is 20 (Good) right now — safe for outdoor activity.

Is it safe to be outside in Deer Lodge today?

AQI 20 Yes — air quality is Good

Air is clean — great for outdoor activity.Main pollutant: PM2.5Observed 8:00 AM MDT

Pollutants right now

ExerciseOK to run — no air-quality limits on outdoor exercise.

How to read Deer Lodge’s air quality

Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.

Air quality over time in Deer Lodge

Across the EPA’s county records from 2020 to 2025, Deer Lodge’s cleanest year was 2020 (median AQI 3) and its most polluted was 2023 (median AQI 14); the typical (median) day has trended more polluted since 2020.

Deer Lodge’s county air-quality record by year — the median and days in each AQI category, from the EPA’s Annual AQI by County summaries.
YearMedian AQIUnhealthy+Main pollutantUSGModerateGood
202030PM2.50033
2021120PM2.5313101
2022120PM2.518105
2023140PM2.527100
2024120PM2.5211101
2025130PM2.50590

“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 20202025.

Frequently asked

What was the worst year for air quality in Deer Lodge?
In the EPA's 2020–2025 county records, 2021 had the most days above AQI 100: 3 days (3 Unhealthy for Sensitive Groups, 0 Unhealthy or worse). The highest median AQI came in 2023 (14; 2021's was 12).
How many unhealthy air days does Deer Lodge have?
Across 2020–2025, 1% of the days reported for Deer Lodge's county had an AQI above 100 (8 of 582), about 1 day a year. 2025 had 0 days.
What's the main air pollutant in Deer Lodge?
PM2.5: it drove Deer Lodge's county AQI on the most days in every year of the EPA's 2020–2025 records.