Median AQI
10
Good
Wyoming · County air quality · 2025
Washakie County, Wyoming
Median AQI 10 (Good). 98.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 10
- Median AQI
- 98.0%
- Good-air days
- 0
- Unhealthy days
- 95%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Washakie County's air is good on balance, among the cleanest 5% of US counties, a median AQI of 10 with 98.0% of 202 monitored days in the Good band, driven mainly by PM2.5.
- 10
- median AQI · Good
- 98.0%
- days rated Good
- PM2.5
- main pollutant
- 95%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 59.
Data updated July 2026
- Good · 198 d · 98.0%
- Moderate · 4 d · 2.0%
How did Washakie County's air break down in 2025?
Across 202 monitored days, 198 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 59 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 202 days monitored. Median AQI: 10 (Good).
Insights: Washakie County, Wyoming. EPA monitors recorded a median Air Quality Index of 10 across 202 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 198 (98%) fell in the Good band (AQI 0–50), 4 (2%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 23, while the worst single-day peak hit 59 (Moderate). Residents averaged about 29.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (202 days). Across the 2024–2025 trend window, good days shifted by -111 and the median AQI moved +2 points, placing the multi-year trajectory at improving. The worst single reading over the 2024–2025 window was AQI 59, moderate but never Unhealthy. Nearby counties show comparable readings: Albany (51.9% good, AQI 50); Campbell (77.3% good, AQI 43); Carbon (100.0% good, AQI 7); Converse (94.5% good, AQI 41); Fremont (61.3% good, AQI 48); Johnson (90.6% good, AQI 42).
Air Quality Summary
Good Days
98.0%
198 of 202 monitored days
23.0pp vs 75% target
Max AQI Recorded
59
Moderate
Health Grade
Excellent
90th-pct AQI 23
Washakie County, Good days share 98.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Washakie 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 202 monitored days across EPA AQI categories.
Good
198
98%
Moderate
4
2%
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 Washakie County.
- PM2.5 · 202 days · 100.0%
Health Impact Assessment
Excellent
Washakie County's air quality is rated Excellent based on 98.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 98.0% of monitored days in 2025, with a median AQI of 10. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 202 of 202 monitored days.
5-Year Air Quality Trend
Air quality is improving in Washakie County. Best year: 2024 (309 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2024 | 309 | 20 | 0 | 0 | 8 | 83 |
| 2025 | 198 | 4 | 0 | 0 | 10 | 59 |
How does Washakie County compare?
How Washakie County compares
Good-day share better than US avg
Washakie County 98.0%
Albany County, Wyoming 51.9%
US average 76.5%
Median AQI better than US avg
Washakie County 10
Albany County, Wyoming 50
US average 38
Unhealthy days / yr about average
Washakie 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 Washakie County.
Lincoln County, Wyoming
AQI 10 · 97.8% good
Los Alamos County, New Mexico
AQI 10 · 100.0% good
Uinta County, Wyoming
AQI 10 · 100.0% good
Aleutians East County, Alaska
AQI 11 · 95.0% good
Carroll County, Virginia
AQI 9 · 100.0% good
Dakota County, Minnesota
AQI 9 · 93.4% good
What Washakie County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 10 means for exposure. Health guidance
- See how Washakie County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Washakie County with its Wyoming neighbours before drawing a conclusion about the region. All of Wyoming
Based on 202 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 Washakie County, Wyoming? ▼
Washakie County has a median Air Quality Index (AQI) of 10, rated "Good." 98.0% of monitored days (198 out of 202) had good air quality in 2025.
What is the main pollutant in Washakie County? ▼
The primary pollutant in Washakie County is Fine Particles (PM2.5), which was the main AQI driver on 202 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Washakie County have? ▼
In 2025, Washakie County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 59.
Is the air quality in Washakie County getting better or worse? ▼
Air quality in Washakie County is improving based on 5-year trends (2024-2025). Best year: 2024 with 309 good days. Worst year: 2025 with 198 good days.
What does AQI 10 mean for health? ▼
Washakie County's median AQI of 10 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 Washakie County compare to other counties in Wyoming? ▼
Washakie County has 98.0% good air days. Nearby counties in Wyoming: Albany (51.9% good), Campbell (77.3% good), Carbon (100.0% good), Converse (94.5% good), Fremont (61.3% good), Johnson (90.6% good).
What is the 90th percentile AQI in Washakie County? ▼
The 90th percentile AQI for Washakie County is 23, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 59 (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.