Cheyenne Air Quality in October
Across 2019–2025, Cheyenne's October air quality had a median AQI of 41 (Good) over 217 monitored days in the Cheyenne, WY area. 1.9% of October days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 80.6% of days. The cleanest October on record here was 2022 (median AQI 38, 0 days above 100) and the worst was 2020 (median 42, 4 days above 100, peak AQI 159).
- Good: 86.2%
- Moderate: 12.0%
- Unhealthy for Sensitive Groups: 1.4%
- Unhealthy or worse: 0.5%
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 October?
Good on a typical day: median AQI 41 across 2019–2025, with 1.9% of October days above AQI 100. Ground-level ozone is the main driver.
- ✓86.2% of October days were Good (AQI 0–50), 12.0% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the October peak was 159.
- ✓Best October: 2022; worst October: 2020.
Frequently asked questions
What is the air quality like in Cheyenne in October?▾
Across 2019–2025, the median daily AQI in Cheyenne in October was 41 (Good). 86.2% of days were Good, 12.0% Moderate, and 1.9% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Cheyenne?▾
A typical October day in Cheyenne sits in the Good range (median AQI 41), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 53 of October days (1.9%) reached AQI 101+ in 2019–2025.
Which pollutant causes Cheyenne's October air quality problems?▾
Ground-level ozone set the daily AQI on 80.6% of October days in Cheyenne. The highest October AQI recorded in 2019–2025 was 159 (Unhealthy), in 2020.
Cheyenne October air quality, year by year
Cheyenne October air quality by year (Cheyenne, WY, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 42 | 0 | 71 | O3 |
| 2020worst | 31 | 42 | 4 | 159 | O3 |
| 2021 | 31 | 42 | 0 | 58 | O3 |
| 2022cleanest | 31 | 38 | 0 | 46 | O3 |
| 2023 | 31 | 41 | 0 | 51 | O3 |
| 2024 | 31 | 45 | 0 | 65 | O3 |
| 2025 | 31 | 41 | 0 | 49 | O3 |
What October air means in Cheyenne
A typical October day in Cheyenne sits in the Good range (median AQI 41), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 53 of October days (1.9%) reached AQI 101+ in 2019–2025.
October's median AQI of 41 is in line with Cheyenne's whole-year median of 44, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Cheyenne runs in line with the national October norm; 1.9% of its October days topped AQI 100 versus 1.3% nationally (about the same).
October is part of Cheyenne's fall season (September, October, November); the fall page pools all three months.
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 month 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.