Median AQI
43
Good
Wyoming · County air quality · 2025
Campbell County, Wyoming
Median AQI 43 (Good). 77.3% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 77.3%
- Good-air days
- 0
- Unhealthy days
- 45%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Campbell County's air is good on balance, more polluted than the median US county, a median AQI of 43 with 77.3% of 181 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 77.3%
- days rated Good
- Ozone
- main pollutant
- 45%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 99.
Data updated July 2026
- Good · 140 d · 77.3%
- Moderate · 41 d · 22.7%
How did Campbell County's air break down in 2025?
Across 181 monitored days, 140 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 99 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 181 days monitored. Median AQI: 43 (Good).
Insights: Campbell County, Wyoming. EPA monitors recorded a median Air Quality Index of 43 across 181 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 140 (77%) fell in the Good band (AQI 0–50), 41 (23%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 58, while the worst single-day peak hit 99 (Moderate). Residents averaged about 23.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (134 days), PM10 (42 days), PM2.5 (5 days). Across the 2020–2025 trend window, good days shifted by -107 and the median AQI moved -1 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 99, moderate but never Unhealthy. Nearby counties show comparable readings: Albany (51.9% good, AQI 50); Carbon (100.0% good, AQI 7); Converse (94.5% good, AQI 41); Fremont (61.3% good, AQI 48); Johnson (90.6% good, AQI 42); Laramie (69.8% good, AQI 47).
Air Quality Summary
Good Days
77.3%
140 of 181 monitored days
2.3pp vs 75% target
Max AQI Recorded
99
Moderate
Health Grade
Good
90th-pct AQI 58
Campbell County, Good days share 77.3%
National avg
Share of monitored days at AQI 0-50 (Good band).
Campbell 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
140
77%
Moderate
41
23%
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 Campbell County.
- Ozone · 134 days · 74.0%
- PM10 · 42 days · 23.2%
- PM2.5 · 5 days · 2.8%
Health Impact Assessment
Good
Campbell County's air quality is rated Good based on 77.3% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 77.3% 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 134 of 181 monitored days.
5-Year Air Quality Trend
Air quality is improving in Campbell County. Best year: 2020 (247 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 247 | 116 | 3 | 0 | 44 | 124 |
| 2021 | 218 | 131 | 16 | 0 | 44 | 143 |
| 2022 | 210 | 146 | 7 | 1 | 48 | 584 |
| 2023 | 245 | 113 | 6 | 1 | 45 | 177 |
| 2024 | 232 | 129 | 3 | 2 | 44 | 161 |
| 2025 | 140 | 41 | 0 | 0 | 43 | 99 |
How does Campbell County compare?
How Campbell County compares
Good-day share better than US avg
Campbell County 77.3%
Albany County, Wyoming 51.9%
US average 76.5%
Median AQI worse than US avg
Campbell County 43
Albany County, Wyoming 50
US average 38
Unhealthy days / yr about average
Campbell County 0
Albany County, Wyoming 0
US average 0
Other Counties in Wyoming
Air quality comparison for nearby counties in Wyoming.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Campbell 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 Campbell 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 Campbell County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Campbell County with its Wyoming neighbours before drawing a conclusion about the region. All of Wyoming
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 Campbell County, Wyoming? ▼
Campbell County has a median Air Quality Index (AQI) of 43, rated "Good." 77.3% of monitored days (140 out of 181) had good air quality in 2025.
What is the main pollutant in Campbell County? ▼
The primary pollutant in Campbell County is Ozone (O3), which was the main AQI driver on 134 days (74% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Campbell County have? ▼
In 2025, Campbell County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 99.
Is the air quality in Campbell County getting better or worse? ▼
Air quality in Campbell County is improving based on 5-year trends (2020-2025). Best year: 2020 with 247 good days. Worst year: 2025 with 140 good days.
What does AQI 43 mean for health? ▼
Campbell 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 Campbell County compare to other counties in Wyoming? ▼
Campbell County has 77.3% good air days. Nearby counties in Wyoming: Albany (51.9% good), Carbon (100.0% good), Converse (94.5% good), Fremont (61.3% good), Johnson (90.6% good), Laramie (69.8% good).
What is the 90th percentile AQI in Campbell County? ▼
The 90th percentile AQI for Campbell County is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 99 (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.