Boise, Idaho Air Quality
Boise air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now
Boise, ID · Air quality right now
The air quality index in Boise, ID is 16 (Good) right now — safe for outdoor activity.
Is it safe to be outside in Boise today?
AQI 16 Yes — air quality is Good
Air is clean — great for outdoor activity.Main pollutant: PM2.5Observed 9:00 AM MDT
Pollutants right now
- PM2.53.7 µg/m³Main pollutantfine particles — smoke, exhaust, soot
- PM104.0 µg/m³coarse particles — dust, pollen, ash
- Ozone32 µg/m³smog — builds on hot, sunny days
- NO₂9.7 µg/m³nitrogen dioxide — traffic, combustion
ExerciseOK to run — no air-quality limits on outdoor exercise.
How to read Boise’s air quality
Guides: The AQI Scale, Explained · Air Quality Alerts, Decoded · How to Read a Wildfire Smoke Map · Why Wildfire Smoke Travels 1,000 Miles.
Air quality over time in Boise
Across the EPA’s county records from 2020 to 2025, Boise’s cleanest year was 2025 (median AQI 42) and its most polluted was 2022 (median AQI 48); the typical (median) day has trended cleaner since 2020.
| Year | Median AQI | Unhealthy+ | Main pollutant | USG | Moderate | Good |
|---|---|---|---|---|---|---|
| 2020 | 44 | 7 | PM2.5 | 11 | 106 | 242 |
| 2021 | 46 | 3 | Ozone | 15 | 124 | 223 |
| 2022 | 48 | 1 | Ozone | 6 | 162 | 196 |
| 2023 | 44 | 0 | Ozone | 3 | 111 | 251 |
| 2024 | 44 | 7 | Ozone | 28 | 101 | 230 |
| 2025 | 42 | 0 | Ozone | 0 | 95 | 270 |
“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.
Frequently asked
- What was the worst year for air quality in Boise?
- In the EPA's 2020–2025 county records, 2024 had the most days above AQI 100: 35 days (28 Unhealthy for Sensitive Groups, 7 Unhealthy or worse). The highest median AQI came in 2022 (48; 2024's was 44).
- How many unhealthy air days does Boise have?
- Across 2020–2025, 4% of the days reported for Boise's county had an AQI above 100 (81 of 2192), about 14 days a year. 2025 had 0 days.
- What's the main air pollutant in Boise?
- Ozone drove Boise's county AQI on the most days in 5 of 6 years (2020–2025); PM2.5 in 2020.