Cheyenne Air Quality in Summer
Across 2019–2025, Cheyenne's summer (June–August) air quality had a median AQI of 49 (Good) over 642 monitored days in the Cheyenne, WY area. 2.4% of summer days (15 of 642) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 86.8% of days. The cleanest summer on record here was 2020 (median AQI 38, 0 days above 100) and the worst was 2021 (median 66, 11 days above 100, peak AQI 126).
- Good: 55.8%
- Moderate: 41.9%
- Unhealthy for Sensitive Groups: 2.2%
- Unhealthy or worse: 0.2%
Reduce Indoor Ozone in Cheyenne
Today's main pollutant in Cheyenne is ground-level ozone (AQI 31). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Cheyenne in summer?
Good on a typical day: median AQI 49 across 2019–2025, with 2.4% of summer days above AQI 100. Ground-level ozone is the main driver.
- ✓55.8% of summer days were Good (AQI 0–50), 41.9% Moderate (51–100).
- ✓15 days of 642 reached AQI 101+; the summer peak was 151.
- ✓Cleanest month: June; worst month: July.
Frequently asked questions
What is the air quality like in Cheyenne in summer?▾
Across 2019–2025, the median daily AQI in Cheyenne in summer was 49 (Good). 55.8% of days were Good, 41.9% Moderate, and 2.4% reached Unhealthy for Sensitive Groups or worse, based on 642 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Cheyenne?▾
A typical summer day in Cheyenne sits in the Good range (median AQI 49), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 42 of summer days (2.4%) reached AQI 101+ in 2019–2025.
Which pollutant causes Cheyenne's summer air quality problems?▾
Ground-level ozone set the daily AQI on 86.8% of summer days in Cheyenne. The highest summer AQI recorded in 2019–2025 was 151 (Unhealthy), in 2021.
Cheyenne summer air quality, year by year
Cheyenne summer air quality by year (Cheyenne, WY, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 92 | 48 | 0 | 74 | O3 |
| 2020cleanest | 92 | 38 | 0 | 98 | O3 |
| 2021worst | 92 | 66 | 11 | 126 | O3 |
| 2022 | 90 | 50 | 0 | 90 | O3 |
| 2023 | 92 | 49 | 0 | 80 | O3 |
| 2024 | 92 | 51 | 4 | 151 | O3 |
| 2025 | 92 | 50 | 0 | 90 | O3 |
What summer air means in Cheyenne
A typical summer day in Cheyenne sits in the Good range (median AQI 49), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 42 of summer days (2.4%) reached AQI 101+ in 2019–2025.
Summer's median AQI of 49 is above Cheyenne's whole-year median of 44, making it one of the area's dirtier periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Cheyenne runs in line with the national Summer norm; 2.4% of its Summer days topped AQI 100 versus 3.6% nationally (below average).
Within the season, June is the cleanest month (median AQI 48, 0.0% of days above 100) and July the worst (median 50, 5.1% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Cheyenne
The latest EPA AirNow observation puts Cheyenne's AQI at 31 (O3). The figures above are multi-year season statistics, not today's reading.
View current Cheyenne air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Cheyenne, WY), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.