Metro area air quality · 2025
Boise City, ID
Median AQI 51 (Moderate). 49.9% of monitored days rated Good across this metro's EPA monitoring network.
- 51
- Median AQI
- 49.9%
- Good-air days
- 0
- Unhealthy days
- 12%
- Cleaner than US metros
Boise City, ID posted a 2025 median AQI of 51 (Moderate) with 49.9% Good days
According to the U.S. EPA Air Quality System, the Boise City, ID CBSA recorded a median AQI of 51 across 365 monitored days in 2025, with 49.9% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US metros
- The Boise City, ID CBSA's 49.9% Good-day share places it cleaner than 12% of US metros in 2025.
- Closest median-AQI peer
- Hot Springs, AR (49.2% Good, median AQI 51) is the closest nationwide median-AQI peer to Boise City, ID.
- 2020–2025 Good-day shift
- Boise City, ID's Good-day share moved +10.0 points from 2020 to 2025 (median AQI -3).
- Median AQI
- Median AQI: 51
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
The Boise City, ID metro runs moderate on the EPA scale, among the more polluted US metros, a median AQI of 51 with 49.9% of 365 monitored days in the Good band.
- 51
- median AQI · Moderate
- 49.9%
- days rated Good
- 12%
- cleaner than US metros
- 135
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Boise City, ID metro's Unhealthy-category days fell from 31 to 0 between the 2024 and 2025 EPA annual releases, a change of -31 days.
- Boise City, ID metro's peak single-day AQI fell from 265 to 135 between the 2024 and 2025 EPA annual releases, a change of -130 points.
- Boise City, ID metro's Good-day share rose from 44.7% to 50.0% between the 2024 and 2025 EPA annual releases, a change of +5.3 percentage points.
- Boise City, ID metro's median AQI fell from 54 to 51 between the 2024 and 2025 EPA annual releases, a change of -3 points.
Insights: Boise City, ID metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 51 over 365 measured days in 2025, which corresponds to a Moderate band and a Poor metro-wide health grade. The monitored-day split lands at 182 Good days (50%), 182 Moderate (50%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 68 while the highest single-day reading hit 135 (USG). Metro residents averaged roughly 15.0 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +10.0 points and the median AQI moved -3 points, which classifies the multi-year trajectory as improving. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Hot Springs, AR (49.2% good, AQI 51); Kansas City, MO-KS (49.3% good, AQI 51); Laredo, TX (49.9% good, AQI 51).
Air Quality Summary
Median AQI
51
Moderate
Good Days
49.9%
182 of 365 days
Max AQI
135
USG
Health Grade
Poor
90th pct: 68
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
182
50%
Moderate
182
50%
USG
1
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Boise City, ID metro area's air quality is rated Poor based on 49.9% good air days. No unhealthy air days were recorded in 2025.
Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.
How does the Boise City, ID metro compare?
How Boise City, ID compares
5-Year Air Quality Trend
Air quality is improving in the Boise City, ID metro. Highest Good-day share: 2025 (50.0%, 182 of 364 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 142 | 203 | 10 | 54 | 223 |
| 2021 | 131 | 214 | 4 | 54 | 173 |
| 2022 | 132 | 220 | 2 | 55 | 188 |
| 2023 | 180 | 182 | 0 | 51 | 120 |
| 2024 | 147 | 151 | 31 | 54 | 265 |
| 2025 | 182 | 182 | 0 | 51 | 135 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Boise City, ID (51).
Hot Springs, AR
Median AQI 51 · 49.2% Good-day share
Kansas City, MO-KS
Median AQI 51 · 49.3% Good-day share
Laredo, TX
Median AQI 51 · 49.9% Good-day share
Modesto, CA
Median AQI 51 · 49.9% Good-day share
Tulsa, OK
Median AQI 51 · 49.6% Good-day share
Waco, TX
Median AQI 51 · 46.6% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Boise City, ID's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
More Air Quality Data
Explore EPA air quality rankings and guides across U.S. metros and counties.
Cleanest Metro Areas
U.S. metros ranked by their share of Good air-quality days.
Worst Air Quality
Counties and metros with the most unhealthy air days.
All Metro Areas
Annual AQI by CBSA for every monitored U.S. metro area.
Best and Worst City Air
What drives urban air quality and how metro areas compare.
Air Quality Guides
Frequently Asked Questions
What is the air quality in the Boise City, ID metro area? ▼
How many unhealthy air days does Boise City, ID have? ▼
Is air quality in Boise City, ID getting better or worse? ▼
What does AQI 51 mean for health? ▼
What is the 90th percentile AQI for Boise City, ID? ▼
How does Boise City, ID compare to other metro areas? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025
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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.