Median AQI
47
Good
Wyoming · County air quality · 2025
Laramie County, Wyoming
Median AQI 47 (Good). 69.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 47
- Median AQI
- 69.8%
- Good-air days
- 0
- Unhealthy days
- 31%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Laramie County's air is good on balance, more polluted than the median US county, a median AQI of 47 with 69.8% of 182 monitored days in the Good band, driven mainly by Ozone.
- 47
- median AQI · Good
- 69.8%
- days rated Good
- Ozone
- main pollutant
- 31%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 108.
Data updated July 2026
- Good · 127 d · 69.8%
- Moderate · 54 d · 29.7%
- USG · 1 d · 0.5%
How did Laramie County's air break down in 2025?
Across 182 monitored days, 127 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 108 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 182 days monitored. Median AQI: 47 (Good).
Insights: Laramie County, Wyoming. EPA monitors recorded a median Air Quality Index of 47 across 182 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 127 (70%) fell in the Good band (AQI 0–50), 54 (30%) registered Moderate readings, and 1 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 67, while the worst single-day peak hit 108 (USG). Residents averaged about 20.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (171 days), PM2.5 (9 days), NO2 (1 days), CO (1 days). Across the 2020–2025 trend window, good days shifted by -186 and the median AQI moved +8 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 108, usg 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
69.8%
127 of 182 monitored days
-5.2pp vs 75% target
Max AQI Recorded
108
USG
Health Grade
Moderate
90th-pct AQI 67
Laramie County, Good days share 69.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Laramie 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 182 monitored days across EPA AQI categories.
Good
127
70%
Moderate
54
30%
USG
1
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 Laramie County.
- Ozone · 171 days · 94.0%
- PM2.5 · 9 days · 4.9%
- NO₂ · 1 days · 0.5%
- CO · 1 days · 0.5%
Health Impact Assessment
Moderate
Laramie County's air quality is rated Moderate based on 69.8% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 69.8% of monitored days in 2025, with a median AQI of 47. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 171 of 182 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Laramie County. Best year: 2020 (313 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 313 | 48 | 3 | 2 | 39 | 159 |
| 2021 | 261 | 92 | 11 | 0 | 44 | 126 |
| 2022 | 297 | 66 | 0 | 0 | 42 | 90 |
| 2023 | 275 | 85 | 4 | 1 | 45 | 156 |
| 2024 | 271 | 91 | 3 | 1 | 45 | 151 |
| 2025 | 127 | 54 | 1 | 0 | 47 | 108 |
How does Laramie County compare?
How Laramie County compares
Good-day share worse than US avg
Laramie County 69.8%
Albany County, Wyoming 51.9%
US average 76.5%
Median AQI worse than US avg
Laramie County 47
Albany County, Wyoming 50
US average 38
Unhealthy days / yr about average
Laramie 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 Laramie County.
Beaver County, Pennsylvania
AQI 47 · 54.3% good
Bell County, Texas
AQI 47 · 61.3% good
Bowie County, Texas
AQI 47 · 57.3% good
Bronx County, New York
AQI 47 · 56.6% good
Butte County, California
AQI 47 · 66.1% good
Calcasieu County, Louisiana
AQI 47 · 61.5% good
What Laramie 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 47 means for exposure. Health guidance
- See how Laramie County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Laramie County with its Wyoming neighbours before drawing a conclusion about the region. All of Wyoming
Based on 182 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 Laramie County, Wyoming? ▼
Laramie County has a median Air Quality Index (AQI) of 47, rated "Good." 69.8% of monitored days (127 out of 182) had good air quality in 2025.
What is the main pollutant in Laramie County? ▼
The primary pollutant in Laramie County is Ozone (O3), which was the main AQI driver on 171 days (94% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Laramie County have? ▼
In 2025, Laramie County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 108.
Is the air quality in Laramie County getting better or worse? ▼
Air quality in Laramie County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 313 good days. Worst year: 2025 with 127 good days.
What does AQI 47 mean for health? ▼
Laramie County's median AQI of 47 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 Laramie County compare to other counties in Wyoming? ▼
Laramie County has 69.8% 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 Laramie County? ▼
The 90th percentile AQI for Laramie County is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 108 (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.