Billings Air Quality in November

Across 2019–2025, Billings's November air quality had a median AQI of 33 (Good) over 206 monitored days in the Billings, MT area. 0.0% of November days (0 of 206) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 84.5% of days. The cleanest November on record here was 2025 (median AQI 28, 0 days above 100) and the worst was 2020 (median 39, 0 days above 100, peak AQI 58).

33
Median AQI
Good
0.0%
Days above AQI 100
0 of 206 days
51
90th percentile AQI
worst 1 day in 10
77
Peak AQI
Moderate
PM2.5
Main pollutant
84.5% of days
89.3%
Good days
184 of 206
  • Good: 89.3%
  • Moderate: 10.7%
  • 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.

Recommended: Levoit Core 300True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft

Check Price on Amazon →

As an Amazon Associate, we earn from qualifying purchases.

QUICK ANSWER

How is the air in Billings in November?

Good on a typical day: median AQI 33 across 2019–2025, with 0.0% of November days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 89.3% of November days were Good (AQI 0–50), 10.7% Moderate (51–100).
  • 0 days of 206 reached AQI 101+; the November peak was 77.
  • Best November: 2025; worst November: 2020.

Frequently asked questions

What is the air quality like in Billings in November?

Across 2019–2025, the median daily AQI in Billings in November was 33 (Good). 89.3% of days were Good, 10.7% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 206 monitored days in EPA's Air Quality System.

Is November a good time for outdoor exercise in Billings?

A typical November day in Billings sits in the Good range (median AQI 33), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of November days reached AQI 101+ in 2019–2025.

Which pollutant causes Billings's November air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 84.5% of November days in Billings. The highest November AQI recorded in 2019–2025 was 77 (Moderate), in 2020.

Billings November air quality, year by year

Billings November air quality by year (Billings, MT, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193031050PM2.5
2020worst3039058PM2.5
20212833052PM2.5
20223037056PM2.5
20232835056PM2.5
20243031071PM2.5
2025cleanest3028077O3

What November air means in Billings

A typical November day in Billings sits in the Good range (median AQI 33), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of November days reached AQI 101+ in 2019–2025.

November's median AQI of 33 is below Billings's whole-year median of 38, making it one of the area's cleaner periods. Nationally, the median November AQI across every EPA metro area (92,704 metro-days, 2019–2025) is 39, so Billings runs below the national November norm; 0.0% of its November days topped AQI 100 versus 0.6% nationally (about the same).

November is part of Billings's fall season (September, October, November); the fall 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.