Billings Air Quality in March
Across 2019–2025, Billings's March air quality had a median AQI of 35 (Good) over 182 monitored days in the Billings, MT area. 0.0% of March days (0 of 182) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 73.6% of days. The cleanest March on record here was 2022 (median AQI 26, 0 days above 100) and the worst was 2023 (median 46, 0 days above 100, peak AQI 65).
- Good: 91.2%
- Moderate: 8.8%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Billings
Today's main pollutant in Billings is ground-level ozone (AQI 21). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
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How is the air in Billings in March?
Good on a typical day: median AQI 35 across 2019–2025, with 0.0% of March days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓91.2% of March days were Good (AQI 0–50), 8.8% Moderate (51–100).
- ✓0 days of 182 reached AQI 101+; the March peak was 65.
- ✓Best March: 2022; worst March: 2023.
Frequently asked questions
What is the air quality like in Billings in March?▾
Across 2019–2025, the median daily AQI in Billings in March was 35 (Good). 91.2% of days were Good, 8.8% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 182 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Billings?▾
A typical March day in Billings sits in the Good range (median AQI 35), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.
Which pollutant causes Billings's March air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 73.6% of March days in Billings. The highest March AQI recorded in 2019–2025 was 65 (Moderate), in 2023.
Billings March air quality, year by year
Billings March air quality by year (Billings, MT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2020 | 31 | 33 | 0 | 59 | PM2.5 |
| 2021 | 30 | 28 | 0 | 47 | PM2.5 |
| 2022cleanest | 31 | 26 | 0 | 51 | PM2.5 |
| 2023worst | 28 | 46 | 0 | 65 | PM2.5 |
| 2024 | 31 | 37 | 0 | 52 | O3 |
| 2025 | 31 | 38 | 0 | 45 | O3 |
What March air means in Billings
A typical March day in Billings sits in the Good range (median AQI 35), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of March days reached AQI 101+ in 2019–2025.
March's median AQI of 35 is in line with Billings's whole-year median of 38, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Billings runs below the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Billings's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Billings
The latest EPA AirNow observation puts Billings's AQI at 21 (O3). The figures above are multi-year month statistics, not today's reading.
View current Billings air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Billings, MT), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.