Boise Air Quality in April
Across 2019–2025, Boise's April air quality had a median AQI of 44 (Good) over 210 monitored days in the Boise City, ID area. 0.0% of April days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 71.9% of days. The cleanest April on record here was 2019 (median AQI 38, 0 days above 100) and the worst was 2025 (median 50, 0 days above 100, peak AQI 80).
- Good: 77.6%
- Moderate: 22.4%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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 April?
Good on a typical day: median AQI 44 across 2019–2025, with 0.0% of April days above AQI 100. Ground-level ozone is the main driver.
- ✓77.6% of April days were Good (AQI 0–50), 22.4% Moderate (51–100).
- ✓0 days of 210 reached AQI 101+; the April peak was 90.
- ✓Best April: 2019; worst April: 2025.
Frequently asked questions
What is the air quality like in Boise in April?▾
Across 2019–2025, the median daily AQI in Boise in April was 44 (Good). 77.6% of days were Good, 22.4% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is April a good time for outdoor exercise in Boise?▾
A typical April day in Boise sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of April days reached AQI 101+ in 2019–2025.
Which pollutant causes Boise's April air quality problems?▾
Ground-level ozone set the daily AQI on 71.9% of April days in Boise. The highest April AQI recorded in 2019–2025 was 90 (Moderate), in 2025.
Boise April air quality, year by year
Boise April air quality by year (Boise City, ID, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 30 | 38 | 0 | 52 | O3 |
| 2020 | 30 | 43 | 0 | 65 | O3 |
| 2021 | 30 | 46 | 0 | 61 | PM2.5 |
| 2022 | 30 | 45 | 0 | 67 | O3 |
| 2023 | 30 | 45 | 0 | 90 | O3 |
| 2024 | 30 | 45 | 0 | 71 | O3 |
| 2025worst | 30 | 50 | 0 | 80 | O3 |
What April air means in Boise
A typical April day in Boise sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of April days reached AQI 101+ in 2019–2025.
April's median AQI of 44 is below Boise's whole-year median of 54, making it one of the area's cleaner periods. Nationally, the median April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Boise runs in line with the national April norm; 0.0% of its April days topped AQI 100 versus 0.7% nationally (about the same).
April is part of Boise's spring season (March, April, May); the spring 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.