Metro area air quality · 2025
Oxnard-Thousand Oaks-Ventura, CA
Median AQI 50 (Good). 52.8% of monitored days rated Good across this metro's EPA monitoring network.
- 50
- Median AQI
- 52.8%
- Good-air days
- 0
- Unhealthy days
- 15%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2025), 273 monitored days. EPA AQS →
The verdict
The Oxnard-Thousand Oaks-Ventura, CA metro runs good on the EPA scale, among the more polluted US metros, a median AQI of 50 with 52.8% of 273 monitored days in the Good band.
- 50
- median AQI · Good
- 52.8%
- days rated Good
- 15%
- cleaner than US metros
- 131
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Insights: Oxnard-Thousand Oaks-Ventura, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 50 over 273 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 144 Good days (53%), 121 Moderate (44%), and 8 Unhealthy-for-Sensitive-Groups (3%). The 90th-percentile AQI finished at 71 while the highest single-day reading hit 131 (USG). Metro residents averaged roughly 15.8 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, good days shifted by -41 and the median AQI moved +0 points, which classifies the multi-year trajectory as stable. 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 Birmingham-Hoover, AL (51.9% good, AQI 50); Boulder, CO (50.9% good, AQI 50); Durango, CO (53.3% good, AQI 50).
Air Quality Summary
Median AQI
50
Good
Good Days
52.8%
144 of 273 days
Max AQI
131
USG
Health Grade
Moderate
90th pct: 71
AQI Day Breakdown (2025)
Distribution of 273 monitored days across EPA AQI categories.
Good
144
53%
Moderate
121
44%
USG
8
3%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Oxnard-Thousand Oaks-Ventura, CA metro area's air quality is rated Moderate based on 52.8% 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 Oxnard-Thousand Oaks-Ventura, CA metro compare?
How Oxnard-Thousand Oaks-Ventura, CA compares
5-Year Air Quality Trend
Air quality is stable in the Oxnard-Thousand Oaks-Ventura, CA metro. Best year: 2023 (220 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 185 | 155 | 5 | 50 | 174 |
| 2021 | 157 | 198 | 0 | 53 | 122 |
| 2022 | 171 | 183 | 0 | 52 | 140 |
| 2023 | 220 | 133 | 0 | 46 | 136 |
| 2024 | 191 | 160 | 1 | 50 | 176 |
| 2025 | 144 | 121 | 0 | 50 | 131 |
Metros with Similar Air Quality
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Air Quality Guides
Frequently Asked Questions
What is the air quality in the Oxnard-Thousand Oaks-Ventura, CA metro area? ▼
How many unhealthy air days does Oxnard-Thousand Oaks-Ventura, CA have? ▼
Is air quality in Oxnard-Thousand Oaks-Ventura, CA getting better or worse? ▼
What does AQI 50 mean for health? ▼
What is the 90th percentile AQI for Oxnard-Thousand Oaks-Ventura, CA? ▼
How does Oxnard-Thousand Oaks-Ventura, 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.