Metro area air quality · 2025
Clearlake, CA
Median AQI 17 (Good). 100.0% of monitored days rated Good across this metro's EPA monitoring network.
- 17
- Median AQI
- 100.0%
- Good-air days
- 0
- Unhealthy days
- 98%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2025), 34 monitored days. EPA AQS →
The verdict
The Clearlake, CA metro runs good on the EPA scale, among the cleanest 10% of US metros, a median AQI of 17 with 100.0% of 34 monitored days in the Good band.
- 17
- median AQI · Good
- 100.0%
- days rated Good
- 98%
- cleaner than US metros
- 32
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Insights: Clearlake, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 17 over 34 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 34 Good days (100%), 0 Moderate (0%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 29 while the highest single-day reading hit 32 (Good). Metro residents averaged roughly 30.0 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, good days shifted by -307 and the median AQI moved -15 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 Centralia, WA (93.3% good, AQI 18); Guayama, PR (100.0% good, AQI 18); Marquette, MI (87.0% good, AQI 18).
Air Quality Summary
Median AQI
17
Good
Good Days
100.0%
34 of 34 days
Max AQI
32
Good
Health Grade
Excellent
90th pct: 29
AQI Day Breakdown (2025)
Distribution of 34 monitored days across EPA AQI categories.
Good
34
100%
Moderate
0
0%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Clearlake, CA metro area's air quality is rated Excellent based on 100.0% 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 Clearlake, CA metro compare?
How Clearlake, CA compares
5-Year Air Quality Trend
Air quality is improving in the Clearlake, CA metro. Best year: 2024 (361 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 341 | 6 | 3 | 32 | 190 |
| 2021 | 348 | 7 | 1 | 33 | 157 |
| 2022 | 359 | 4 | 0 | 32 | 76 |
| 2023 | 357 | 6 | 0 | 32 | 67 |
| 2024 | 361 | 2 | 0 | 32 | 67 |
| 2025 | 34 | 0 | 0 | 17 | 32 |
Metros with Similar Air Quality
Metro areas across the US with a similar median AQI to Clearlake, CA.
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Worst Air Quality
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All Metro Areas
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Air Quality Guides
Frequently Asked Questions
What is the air quality in the Clearlake, CA metro area? ▼
How many unhealthy air days does Clearlake, CA have? ▼
Is air quality in Clearlake, CA getting better or worse? ▼
What does AQI 17 mean for health? ▼
What is the 90th percentile AQI for Clearlake, CA? ▼
How does Clearlake, CA 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.