Median AQI
43
Good
Nevada · County air quality · 2025
Churchill County, Nevada
Median AQI 43 (Good). 81.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 81.0%
- Good-air days
- 0
- Unhealthy days
- 55%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Churchill County's air is good on balance, cleaner than the median US county, a median AQI of 43 with 81.0% of 174 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 81.0%
- days rated Good
- Ozone
- main pollutant
- 55%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 77.
Data updated July 2026
- Good · 141 d · 81.0%
- Moderate · 33 d · 19.0%
How did Churchill County's air break down in 2025?
Across 174 monitored days, 141 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 77 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 174 days monitored. Median AQI: 43 (Good).
Insights: Churchill County, Nevada. EPA monitors recorded a median Air Quality Index of 43 across 174 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 141 (81%) fell in the Good band (AQI 0–50), 33 (19%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 61, while the worst single-day peak hit 77 (Moderate). Residents averaged about 24.3 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (174 days). Across the 2020–2025 trend window, good days shifted by -195 and the median AQI moved +3 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 77, moderate but never Unhealthy. Nearby counties show comparable readings: Carson City (79.3% good, AQI 45); Clark (25.6% good, AQI 64); Douglas (90.9% good, AQI 22); Elko (90.8% good, AQI 19); Lyon (83.9% good, AQI 44); Nye (91.2% good, AQI 24).
Air Quality Summary
Good Days
81.0%
141 of 174 monitored days
6.0pp vs 75% target
Max AQI Recorded
77
Moderate
Health Grade
Good
90th-pct AQI 61
Churchill County, Good days share 81.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Churchill 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 174 monitored days across EPA AQI categories.
Good
141
81%
Moderate
33
19%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Churchill County.
- Ozone · 174 days · 100.0%
Health Impact Assessment
Good
Churchill County's air quality is rated Good based on 81.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 81.0% of monitored days in 2025, with a median AQI of 43. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 174 of 174 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Churchill County. Best year: 2020 (336 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 336 | 25 | 2 | 0 | 40 | 147 |
| 2021 | 271 | 81 | 9 | 1 | 44 | 159 |
| 2022 | 330 | 19 | 0 | 0 | 39 | 100 |
| 2023 | 295 | 59 | 0 | 0 | 43 | 90 |
| 2024 | 280 | 77 | 1 | 0 | 44 | 105 |
| 2025 | 141 | 33 | 0 | 0 | 43 | 77 |
How does Churchill County compare?
How Churchill County compares
Good-day share better than US avg
Churchill County 81.0%
Carson City County, Nevada 79.3%
US average 76.5%
Median AQI worse than US avg
Churchill County 43
Carson City County, Nevada 45
US average 38
Unhealthy days / yr about average
Churchill County 0
Carson City County, Nevada 0
US average 0
Other Counties in Nevada
Air quality comparison for nearby counties in Nevada.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Churchill County.
Allegan County, Michigan
AQI 43 · 71.2% good
Allen County, Ohio
AQI 43 · 65.9% good
Ashtabula County, Ohio
AQI 43 · 81.2% good
Bell County, Kentucky
AQI 43 · 63.5% good
Boise County, Idaho
AQI 43 · 72.9% good
Brazos County, Texas
AQI 43 · 63.4% good
What Churchill 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 43 means for exposure. Health guidance
- See how Churchill County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Churchill County with its Nevada neighbours before drawing a conclusion about the region. All of Nevada
Based on 174 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 Churchill County, Nevada? ▼
Churchill County has a median Air Quality Index (AQI) of 43, rated "Good." 81.0% of monitored days (141 out of 174) had good air quality in 2025.
What is the main pollutant in Churchill County? ▼
The primary pollutant in Churchill County is Ozone (O3), which was the main AQI driver on 174 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Churchill County have? ▼
In 2025, Churchill County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 77.
Is the air quality in Churchill County getting better or worse? ▼
Air quality in Churchill County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 336 good days. Worst year: 2025 with 141 good days.
What does AQI 43 mean for health? ▼
Churchill County's median AQI of 43 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 Churchill County compare to other counties in Nevada? ▼
Churchill County has 81.0% good air days. Nearby counties in Nevada: Carson City (79.3% good), Clark (25.6% good), Douglas (90.9% good), Elko (90.8% good), Lyon (83.9% good), Nye (91.2% good).
What is the 90th percentile AQI in Churchill County? ▼
The 90th percentile AQI for Churchill County is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 77 (Moderate).
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.