California · County air quality · 2025

Sacramento County, California

Median AQI 48 (Good). 58.9% of monitored days rated Good, direct from EPA Air Quality System stations.

48
Median AQI
58.9%
Good-air days
0
Unhealthy days
13%
Cleaner than US counties

The verdict

According to EPA Air Quality System monitoring data, Sacramento County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 48 with 58.9% of 224 monitored days in the Good band, driven mainly by Ozone.

48
median AQI · Good
58.9%
days rated Good
Ozone
main pollutant
13%
cleaner than US counties

Not one day crossed into the Unhealthy tier; the worst single reading was AQI 122.

Data updated July 2026

Sacramento County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 224 monitored days G M Median AQI 48 0 50 100 150 200 300 500 Sacramento County
  • Good · 132 d · 58.9%
  • Moderate · 89 d · 39.7%
  • USG · 3 d · 1.3%

How did Sacramento County's air break down in 2025?

Across 224 monitored days, 132 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 122 (USG).

EPA AQS →

Air quality data from EPA Air Quality System (2025). 224 days monitored. Median AQI: 48 (Good).

Insights: Sacramento County, California. EPA monitors recorded a median Air Quality Index of 48 across 224 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 132 (59%) fell in the Good band (AQI 0–50), 89 (40%) registered Moderate readings, and 3 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 71, while the worst single-day peak hit 122 (USG). Residents averaged about 17.7 clean-air days per 30-day window during the monitoring year.

The full pollutant mix ranks as Ozone (129 days), PM2.5 (94 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -13 and the median AQI moved -7 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 122, usg but never Unhealthy. 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

Median AQI

48

Good

Good Days

58.9%

132 of 224 monitored days

-16.1pp vs 75% target

Max AQI Recorded

122

USG

Health Grade

Moderate

90th-pct AQI 71

Sacramento County, Good days share 58.9%
National avg

Share of monitored days at AQI 0-50 (Good band).

Sacramento County, Unhealthy-or-worse share 0.0%
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 224 monitored days across EPA AQI categories.

Good

132

59%

Moderate

89

40%

USG

3

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Sacramento County.

Sacramento County, California criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. Ozone · 57.6% PM2.5 · 42.0% 0% 25% 50% 75% 100% Sacramento County, California · 224 monitored days Criteria pollutant column
  • Ozone · 129 days · 57.6%
  • PM2.5 · 94 days · 42.0%
  • CO · 1 days · 0.4%
Ozone (O3) 129 days (58%)

How Ozone affects health →

Fine Particles (PM2.5) 94 days (42%)

How PM2.5 affects health →

Carbon Monoxide (CO) 1 days (0%)

How CO affects health →

Health Impact Assessment

Moderate

Sacramento County's air quality is rated Moderate based on 58.9% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 58.9% of monitored days in 2025, with a median AQI of 48. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 129 of 224 monitored days.

5-Year Air Quality Trend

Air quality is improving in Sacramento County. Best year: 2024 (182 good days).

Year Good Moderate USG Unhealthy Median AQI
2020 145 185 17 16 55
2021 146 183 30 4 55
2022 162 184 17 2 53
2023 180 173 12 0 51
2024 182 169 15 0 51
2025 132 89 3 0 48

How does Sacramento County compare?

How Sacramento County compares

Good-day share worse than US avg
Sacramento County 58.9%
Amador County, California 84.8%
US average 76.5%
Median AQI worse than US avg
Sacramento County 48
Amador County, California 40
US average 38
Unhealthy days / yr about average
Sacramento County 0
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 Sacramento County.

What Sacramento County's air means for you

The air here stays in the breathable range year-round, with Ozone the main thing to watch.

  • Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 48 means for exposure. Health guidance
  • See how Sacramento County ranks against every monitored U.S. county on Good-day share. County rankings
  • Compare Sacramento County with its California neighbours before drawing a conclusion about the region. All of California

Based on 224 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 Sacramento County, California?
Sacramento County has a median Air Quality Index (AQI) of 48, rated "Good." 58.9% of monitored days (132 out of 224) had good air quality in 2025.
What is the main pollutant in Sacramento County?
The primary pollutant in Sacramento County is Ozone (O3), which was the main AQI driver on 129 days (58% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Sacramento County have?
In 2025, Sacramento County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 122.
Is the air quality in Sacramento County getting better or worse?
Air quality in Sacramento County is improving based on 5-year trends (2020-2025). Best year: 2024 with 182 good days. Worst year: 2025 with 132 good days.
What does AQI 48 mean for health?
Sacramento County's median AQI of 48 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Sacramento County compare to other counties in California?
Sacramento County has 58.9% 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 Sacramento County?
The 90th percentile AQI for Sacramento County is 71, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 122 (USG).

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.