Median AQI
54
Moderate
California · County air quality · 2025
Santa Barbara County, California
Median AQI 54 (Moderate). 29.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 54
- Median AQI
- 29.8%
- Good-air days
- 1
- Unhealthy days
- 1%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Santa Barbara County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 54 with 29.8% of 181 monitored days in the Good band, driven mainly by PM2.5.
- 54
- median AQI · Moderate
- 29.8%
- days rated Good
- PM2.5
- main pollutant
- 1%
- cleaner than US counties
1 day reached Unhealthy or worse; the worst single reading hit AQI 186.
Data updated July 2026
- Good · 54 d · 29.8%
- Moderate · 126 d · 69.6%
- Unhealthy · 1 d · 0.6%
How did Santa Barbara County's air break down in 2025?
Across 181 monitored days, 54 fell in the Good band (AQI 0–50) and 1 reached Unhealthy or worse. The worst single day peaked at AQI 186 (Unhealthy).
EPA AQS →Air quality data from EPA Air Quality System (2025). 181 days monitored. Median AQI: 54 (Moderate).
Insights: Santa Barbara County, California. EPA monitors recorded a median Air Quality Index of 54 across 181 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 54 (30%) fell in the Good band (AQI 0–50), 126 (70%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 63, while the worst single-day peak hit 186 (Unhealthy). Residents averaged about 9.0 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (156 days), Ozone (21 days), PM10 (4 days). Across the 2020–2025 trend window, good days shifted by -145 and the median AQI moved +6 points, placing the multi-year trajectory at worsening. Residents and visitors experienced 1 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Amador (84.8% good, AQI 40); Butte (66.1% good, AQI 47); Calaveras (73.9% good, AQI 43); Colusa (84.9% good, AQI 39); Del Norte (81.0% good, AQI 33); El Dorado (85.8% good, AQI 39).
Air Quality Summary
Good Days
29.8%
54 of 181 monitored days
-45.2pp vs 75% target
Max AQI Recorded
186
Unhealthy
Health Grade
Poor
90th-pct AQI 63
Santa Barbara County, Good days share 29.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Santa Barbara County, Unhealthy-or-worse share 0.6%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 181 monitored days across EPA AQI categories.
Good
54
30%
Moderate
126
70%
USG
0
0%
Unhealthy
1
1%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Santa Barbara County.
- PM2.5 · 156 days · 86.2%
- Ozone · 21 days · 11.6%
- PM10 · 4 days · 2.2%
Health Impact Assessment
Poor
Santa Barbara County's air quality is rated Poor based on 29.8% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 0 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 186. Sensitive groups should monitor real-time conditions at AirNow.gov.
The dominant pollutant is PM2.5, driving AQI on 156 of 181 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Santa Barbara County. Best year: 2021 (240 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 199 | 154 | 9 | 4 | 48 | 174 |
| 2021 | 240 | 124 | 1 | 0 | 44 | 101 |
| 2022 | 198 | 167 | 0 | 0 | 48 | 93 |
| 2023 | 232 | 133 | 0 | 0 | 45 | 95 |
| 2024 | 193 | 171 | 2 | 0 | 49 | 146 |
| 2025 | 54 | 126 | 0 | 1 | 54 | 186 |
How does Santa Barbara County compare?
How Santa Barbara County compares
Good-day share worse than US avg
Santa Barbara County 29.8%
Amador County, California 84.8%
US average 76.5%
Median AQI worse than US avg
Santa Barbara County 54
Amador County, California 40
US average 38
Unhealthy days / yr worse than US avg
Santa Barbara County 1
Amador County, California 0
US average 0
Other Counties in California
Air quality comparison for nearby counties in California.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Santa Barbara County.
Denver County, Colorado
AQI 54 · 44.2% good
Franklin County, Ohio
AQI 54 · 39.8% good
Fresno County, California
AQI 54 · 40.1% good
Hamilton County, Ohio
AQI 54 · 32.1% good
Hidalgo County, Texas
AQI 54 · 36.2% good
Inyo County, California
AQI 54 · 40.7% good
What Santa Barbara County's air means for you
On most days the air here is fine, but PM2.5 drives 1 unhealthy-or-worse day a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 54 means for exposure. Health guidance
- See how Santa Barbara County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Santa Barbara County with its California neighbours before drawing a conclusion about the region. All of California
Based on 181 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Santa Barbara County, California? ▼
Santa Barbara County has a median Air Quality Index (AQI) of 54, rated "Moderate." 29.8% of monitored days (54 out of 181) had good air quality in 2025.
What is the main pollutant in Santa Barbara County? ▼
The primary pollutant in Santa Barbara County is Fine Particles (PM2.5), which was the main AQI driver on 156 days (86% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Santa Barbara County have? ▼
In 2025, Santa Barbara County recorded 1 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 186.
Is the air quality in Santa Barbara County getting better or worse? ▼
Air quality in Santa Barbara County is worsening based on 5-year trends (2020-2025). Best year: 2021 with 240 good days. Worst year: 2025 with 54 good days.
What does AQI 54 mean for health? ▼
Santa Barbara County's median AQI of 54 falls in the "Moderate" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Santa Barbara County compare to other counties in California? ▼
Santa Barbara County has 29.8% good air days. Nearby counties in California: Amador (84.8% good), Butte (66.1% good), Calaveras (73.9% good), Colusa (84.9% good), Del Norte (81.0% good), El Dorado (85.8% good).
What is the 90th percentile AQI in Santa Barbara County? ▼
The 90th percentile AQI for Santa Barbara County is 63, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 186 (Unhealthy).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
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.