Billings Air Quality in Summer
Across 2019–2025, Billings's summer (June–August) air quality had a median AQI of 39 (Good) over 640 monitored days in the Billings, MT area. 2.3% of summer days (15 of 640) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 81.6% of days. The cleanest summer on record here was 2020 (median AQI 28, 1 day above 100) and the worst was 2021 (median 59, 9 days above 100, peak AQI 167).
- Good: 69.7%
- Moderate: 28.0%
- Unhealthy for Sensitive Groups: 1.7%
- Unhealthy or worse: 0.6%
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How is the air in Billings in summer?
Good on a typical day: median AQI 39 across 2019–2025, with 2.3% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓69.7% of summer days were Good (AQI 0–50), 28.0% Moderate (51–100).
- ✓15 days of 640 reached AQI 101+; the summer peak was 167.
- ✓Cleanest month: June; worst month: July.
Frequently asked questions
What is the air quality like in Billings in summer?▾
Across 2019–2025, the median daily AQI in Billings in summer was 39 (Good). 69.7% of days were Good, 28.0% Moderate, and 2.3% reached Unhealthy for Sensitive Groups or worse, based on 640 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Billings?▾
A typical summer day in Billings sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 43 of summer days (2.3%) reached AQI 101+ in 2019–2025.
Which pollutant causes Billings's summer air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 81.6% of summer days in Billings. The highest summer AQI recorded in 2019–2025 was 167 (Unhealthy), in 2021.
Billings summer air quality, year by year
Billings summer air quality by year (Billings, MT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 32 | 1 | 159 | PM2.5 |
| 2020cleanest | 92 | 28 | 1 | 163 | PM2.5 |
| 2021worst | 91 | 59 | 9 | 167 | PM2.5 |
| 2022 | 92 | 35 | 1 | 155 | PM2.5 |
| 2023 | 92 | 24 | 2 | 115 | PM2.5 |
| 2024 | 91 | 51 | 1 | 105 | O3 |
| 2025 | 92 | 42 | 0 | 88 | O3 |
What summer air means in Billings
A typical summer day in Billings sits in the Good range (median AQI 39), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 43 of summer days (2.3%) reached AQI 101+ in 2019–2025.
Summer's median AQI of 39 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 Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Billings runs below the national Summer norm; 2.3% of its Summer days topped AQI 100 versus 3.6% nationally (below average).
Within the season, June is the cleanest month (median AQI 32, 0.0% of days above 100) and July the worst (median 42, 4.7% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Billings
The latest EPA AirNow observation puts Billings's AQI at 34 (PM2.5). The figures above are multi-year season 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.