Boise Air Quality in November
Across 2019–2025, Boise's November air quality had a median AQI of 61 (Moderate) over 210 monitored days in the Boise City, ID area. 1.0% of November days (2 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 96.7% of days. The cleanest November on record here was 2025 (median AQI 55, 0 days above 100) and the worst was 2019 (median 71, 1 day above 100, peak AQI 104).
- Good: 14.3%
- Moderate: 84.8%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.5%
Reduce Indoor Ozone in Boise
Today's main pollutant in Boise is ground-level ozone (AQI 38). 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 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Boise in November?
Moderate on a typical day: median AQI 61 across 2019–2025, with 1.0% of November days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓14.3% of November days were Good (AQI 0–50), 84.8% Moderate (51–100).
- ✓2 days of 210 reached AQI 101+; the November peak was 160.
- ✓Best November: 2025; worst November: 2019.
Frequently asked questions
What is the air quality like in Boise in November?▾
Across 2019–2025, the median daily AQI in Boise in November was 61 (Moderate). 14.3% of days were Good, 84.8% Moderate, and 1.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is November a good time for outdoor exercise in Boise?▾
A typical November day in Boise is Moderate (median AQI 61): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 100 of November days (1.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Boise's November air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 96.7% of November days in Boise. The highest November AQI recorded in 2019–2025 was 160 (Unhealthy), in 2019.
Boise November air quality, year by year
Boise November air quality by year (Boise City, ID, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 30 | 71 | 1 | 104 | PM2.5 |
| 2020 | 30 | 63 | 0 | 86 | PM2.5 |
| 2021 | 30 | 58 | 0 | 84 | PM2.5 |
| 2022 | 30 | 64 | 0 | 92 | PM2.5 |
| 2023 | 30 | 56 | 0 | 88 | PM2.5 |
| 2024 | 30 | 64 | 1 | 160 | PM2.5 |
| 2025cleanest | 30 | 55 | 0 | 70 | PM2.5 |
What November air means in Boise
A typical November day in Boise is Moderate (median AQI 61): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 100 of November days (1.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
November's median AQI of 61 is above Boise's whole-year median of 54, making it one of the area's dirtier periods. Nationally, the median November AQI across every EPA metro area (92,704 metro-days, 2019–2025) is 39, so Boise runs above the national November norm; 1.0% of its November days topped AQI 100 versus 0.6% nationally (about the same).
November is part of Boise's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Boise
The latest EPA AirNow observation puts Boise's AQI at 38 (O3). The figures above are multi-year month statistics, not today's reading.
View current Boise air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Boise City, ID), 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.