Boise Air Quality in Summer
Across 2019–2025, Boise's summer (June–August) air quality had a median AQI of 54 (Moderate) over 644 monitored days in the Boise City, ID area. 10.1% of summer days (65 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 59.2% of days. The cleanest summer on record here was 2019 (median AQI 47, 0 days above 100) and the worst was 2024 (median 91, 40 days above 100, peak AQI 260).
- Good: 39.9%
- Moderate: 50.0%
- Unhealthy for Sensitive Groups: 5.9%
- Unhealthy or worse: 4.2%
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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Boise in summer?
Moderate on a typical day: median AQI 54 across 2019–2025, with 10.1% of summer days above AQI 100. Ground-level ozone is the main driver.
- ✓39.9% of summer days were Good (AQI 0–50), 50.0% Moderate (51–100).
- ✓65 days of 644 reached AQI 101+; the summer peak was 260.
- ✓Cleanest month: June; worst month: August.
Frequently asked questions
What is the air quality like in Boise in summer?▾
Across 2019–2025, the median daily AQI in Boise in summer was 54 (Moderate). 39.9% of days were Good, 50.0% Moderate, and 10.1% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Boise?▾
A typical summer day in Boise is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 10 of summer days (10.1%) 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 summer air quality problems?▾
Ground-level ozone set the daily AQI on 59.2% of summer days in Boise. The highest summer AQI recorded in 2019–2025 was 260 (Very Unhealthy), in 2024.
Boise summer air quality, year by year
Boise summer air quality by year (Boise City, ID, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 92 | 47 | 0 | 100 | PM2.5 |
| 2020 | 92 | 52 | 6 | 162 | PM2.5 |
| 2021 | 92 | 66 | 14 | 173 | O3 |
| 2022 | 92 | 62 | 4 | 126 | O3 |
| 2023 | 92 | 54 | 1 | 102 | O3 |
| 2024worst | 92 | 91 | 40 | 260 | O3 |
| 2025 | 92 | 48 | 0 | 93 | O3 |
What summer air means in Boise
A typical summer day in Boise is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 10 of summer days (10.1%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Summer's median AQI of 54 is in line with Boise's whole-year median of 54, 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 Boise runs above the national Summer norm; 10.1% of its Summer days topped AQI 100 versus 3.6% nationally (above average).
Within the season, June is the cleanest month (median AQI 47, 0.5% of days above 100) and August the worst (median 63, 16.6% above 100).
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 season 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.