Median AQI
53
Moderate
California · County air quality · 2025
Kings County, California
Median AQI 53 (Moderate). 39.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 53
- Median AQI
- 39.8%
- Good-air days
- 0
- Unhealthy days
- 3%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Kings County's air is moderate on balance, among the most polluted counties nationally, a median AQI of 53 with 39.8% of 181 monitored days in the Good band, driven mainly by Ozone.
- 53
- median AQI · Moderate
- 39.8%
- days rated Good
- Ozone
- main pollutant
- 3%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 105.
Data updated July 2026
- Good · 72 d · 39.8%
- Moderate · 106 d · 58.6%
- USG · 3 d · 1.7%
How did Kings County's air break down in 2025?
Across 181 monitored days, 72 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 105 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 181 days monitored. Median AQI: 53 (Moderate).
Insights: Kings County, California. EPA monitors recorded a median Air Quality Index of 53 across 181 measured days in 2025, earning a Moderate classification and a Poor health grade. Of those days, 72 (40%) fell in the Good band (AQI 0–50), 106 (59%) registered Moderate readings, and 3 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 85, while the worst single-day peak hit 105 (USG). Residents averaged about 11.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (90 days), PM2.5 (88 days), PM10 (3 days). Across the 2020–2025 trend window, good days shifted by -4 and the median AQI moved -17 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 105, 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
Good Days
39.8%
72 of 181 monitored days
-35.2pp vs 75% target
Max AQI Recorded
105
USG
Health Grade
Poor
90th-pct AQI 85
Kings County, Good days share 39.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Kings 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 181 monitored days across EPA AQI categories.
Good
72
40%
Moderate
106
59%
USG
3
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Kings County.
- Ozone · 90 days · 49.7%
- PM2.5 · 88 days · 48.6%
- PM10 · 3 days · 1.7%
Health Impact Assessment
Poor
Kings County's air quality is rated Poor based on 39.8% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 39.8% of monitored days in 2025, with a median AQI of 53. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 90 of 181 monitored days.
5-Year Air Quality Trend
Air quality is improving in Kings County. Best year: 2023 (124 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 76 | 220 | 54 | 13 | 70 | 548 |
| 2021 | 84 | 230 | 40 | 10 | 64 | 685 |
| 2022 | 71 | 244 | 48 | 2 | 69 | 187 |
| 2023 | 124 | 213 | 28 | 0 | 58 | 148 |
| 2024 | 100 | 231 | 33 | 2 | 60 | 156 |
| 2025 | 72 | 106 | 3 | 0 | 53 | 105 |
How does Kings County compare?
How Kings County compares
Good-day share worse than US avg
Kings County 39.8%
Amador County, California 84.8%
US average 76.5%
Median AQI worse than US avg
Kings County 53
Amador County, California 40
US average 38
Unhealthy days / yr about average
Kings 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 Kings County.
Bexar County, Texas
AQI 53 · 39.8% good
Cook County, Illinois
AQI 53 · 40.5% good
Cuyahoga County, Ohio
AQI 53 · 43.6% good
Dallas County, Texas
AQI 53 · 41.0% good
Jefferson County, Alabama
AQI 53 · 36.8% good
Lake County, Indiana
AQI 53 · 38.8% good
What Kings 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 53 means for exposure. Health guidance
- See how Kings County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Kings 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 Kings County, California? ▼
Kings County has a median Air Quality Index (AQI) of 53, rated "Moderate." 39.8% of monitored days (72 out of 181) had good air quality in 2025.
What is the main pollutant in Kings County? ▼
The primary pollutant in Kings County is Ozone (O3), which was the main AQI driver on 90 days (50% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Kings County have? ▼
In 2025, Kings County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 105.
Is the air quality in Kings County getting better or worse? ▼
Air quality in Kings County is improving based on 5-year trends (2020-2025). Best year: 2023 with 124 good days. Worst year: 2022 with 71 good days.
What does AQI 53 mean for health? ▼
Kings County's median AQI of 53 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 Kings County compare to other counties in California? ▼
Kings County has 39.8% 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 Kings County? ▼
The 90th percentile AQI for Kings County is 85, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 105 (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.