Metro area air quality · 2025
Twin Falls, ID
Median AQI 24 (Good). 97.2% of monitored days rated Good across this metro's EPA monitoring network.
- 24
- Median AQI
- 97.2%
- Good-air days
- 0
- Unhealthy days
- 96%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2025), 181 monitored days. EPA AQS →
The verdict
The Twin Falls, ID metro runs good on the EPA scale, among the cleanest 10% of US metros, a median AQI of 24 with 97.2% of 181 monitored days in the Good band.
- 24
- median AQI · Good
- 97.2%
- days rated Good
- 96%
- cleaner than US metros
- 105
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Insights: Twin Falls, ID metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 24 over 181 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 176 Good days (97%), 4 Moderate (2%), and 1 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 38 while the highest single-day reading hit 105 (USG). Metro residents averaged roughly 29.2 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, good days shifted by -139 and the median AQI moved +0 points, which classifies the multi-year trajectory as improving. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Albany, OR (84.5% good, AQI 24); Coeur d'Alene, ID (88.4% good, AQI 24); Moscow, ID (99.3% good, AQI 24).
Air Quality Summary
Median AQI
24
Good
Good Days
97.2%
176 of 181 days
Max AQI
105
USG
Health Grade
Excellent
90th pct: 38
AQI Day Breakdown (2025)
Distribution of 181 monitored days across EPA AQI categories.
Good
176
97%
Moderate
4
2%
USG
1
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Twin Falls, ID metro area's air quality is rated Excellent based on 97.2% 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 Twin Falls, ID metro compare?
How Twin Falls, ID compares
5-Year Air Quality Trend
Air quality is improving in the Twin Falls, ID metro. Best year: 2023 (328 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 315 | 44 | 4 | 24 | 163 |
| 2021 | 298 | 56 | 0 | 28 | 144 |
| 2022 | 280 | 71 | 1 | 31 | 155 |
| 2023 | 328 | 16 | 0 | 25 | 80 |
| 2024 | 264 | 76 | 3 | 23 | 158 |
| 2025 | 176 | 4 | 0 | 24 | 105 |
Metros with Similar Air Quality
Metro areas across the US with a similar median AQI to Twin Falls, ID.
More Air Quality Data
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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 Twin Falls, ID metro area? ▼
How many unhealthy air days does Twin Falls, ID have? ▼
Is air quality in Twin Falls, ID getting better or worse? ▼
What does AQI 24 mean for health? ▼
What is the 90th percentile AQI for Twin Falls, ID? ▼
How does Twin Falls, 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
Every figure on PlainAir 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.