Metro area air quality · 2025
Clearlake, CA
Median AQI 31 (Good). 99.2% of monitored days rated Good across this metro's EPA monitoring network.
- 31
- Median AQI
- 99.2%
- Good-air days
- 0
- Unhealthy days
- 99%
- Cleaner than US metros
Clearlake, CA posted a 2025 median AQI of 31 (Good) with 99.2% Good days
According to the U.S. EPA Air Quality System, the Clearlake, CA CBSA recorded a median AQI of 31 across 363 monitored days in 2025, with 99.2% 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 Clearlake, CA CBSA's 99.2% Good-day share places it cleaner than 99% of US metros in 2025.
- Closest median-AQI peer
- Athens, OH (83.4% Good, median AQI 31) is the closest nationwide median-AQI peer to Clearlake, CA.
- 2020–2025 Good-day shift
- Clearlake, CA's Good-day share moved +1.7 points from 2020 to 2025 (median AQI -1).
- Median AQI
- Median AQI: 31
Aggregated from EPA Air Quality System (2025), 363 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 31 with 99.2% of 363 monitored days in the Good band.
- 31
- median AQI · Good
- 99.2%
- days rated Good
- 99%
- cleaner than US metros
- 74
- 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 31 over 363 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 360 Good days (99%), 3 Moderate (1%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 39 while the highest single-day reading hit 74 (Moderate). Metro residents averaged roughly 29.8 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 +1.7 points and the median AQI moved -1 points, which classifies the multi-year trajectory as stable. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Athens, OH (83.4% good, AQI 31); Bellingham, WA (94.0% good, AQI 31); Coeur d'Alene, ID (77.8% good, AQI 31).
Air Quality Summary
Median AQI
31
Good
Good Days
99.2%
360 of 363 days
Max AQI
74
Moderate
Health Grade
Excellent
90th pct: 39
AQI Day Breakdown (2025)
Distribution of 363 monitored days across EPA AQI categories.
Good
360
99%
Moderate
3
1%
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 99.2% 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 Clearlake, CA metro compare?
How Clearlake, CA compares
5-Year Air Quality Trend
Air quality is stable in the Clearlake, CA metro. Highest Good-day share: 2024 (99.4%, 361 of 363 monitored 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 | 360 | 3 | 0 | 31 | 74 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Clearlake, CA (31).
Athens, OH
Median AQI 31 · 83.4% Good-day share
Bellingham, WA
Median AQI 31 · 94.0% Good-day share
Coeur d'Alene, ID
Median AQI 31 · 77.8% Good-day share
Moscow, ID
Median AQI 31 · 83.4% Good-day share
Cookeville, TN
Median AQI 30 · 90.0% Good-day share
Crescent City, CA
Median AQI 32 · 81.8% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Clearlake, CA'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 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 31 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
Share this annual record
Send the source-year summary or download its ready-to-use data card.
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.