Colorado Springs Air Quality in September
Across 2019–2025, Colorado Springs's September air quality had a median AQI of 51 (Moderate) over 210 monitored days in the Colorado Springs, CO area. 1.9% of September days (4 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 90.5% of days. The cleanest September on record here was 2025 (median AQI 47, 0 days above 100) and the worst was 2021 (median 52, 4 days above 100, peak AQI 108).
- Good: 50.0%
- Moderate: 48.1%
- Unhealthy for Sensitive Groups: 1.9%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Colorado Springs
Today's main pollutant in Colorado Springs is ground-level ozone (AQI 41). 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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Colorado Springs in September?
Moderate on a typical day: median AQI 51 across 2019–2025, with 1.9% of September days above AQI 100. Ground-level ozone is the main driver.
- ✓50.0% of September days were Good (AQI 0–50), 48.1% Moderate (51–100).
- ✓4 days of 210 reached AQI 101+; the September peak was 108.
- ✓Best September: 2025; worst September: 2021.
Frequently asked questions
What is the air quality like in Colorado Springs in September?▾
Across 2019–2025, the median daily AQI in Colorado Springs in September was 51 (Moderate). 50.0% of days were Good, 48.1% Moderate, and 1.9% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Colorado Springs?▾
A typical September day in Colorado Springs is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of September days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Colorado Springs's September air quality problems?▾
Ground-level ozone set the daily AQI on 90.5% of September days in Colorado Springs. The highest September AQI recorded in 2019–2025 was 108 (Unhealthy for Sensitive Groups), in 2021.
Colorado Springs September air quality, year by year
Colorado Springs September air quality by year (Colorado Springs, CO, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 49 | 0 | 84 | O3 |
| 2020 | 30 | 64 | 0 | 90 | O3 |
| 2021worst | 30 | 52 | 4 | 108 | O3 |
| 2022 | 30 | 48 | 0 | 90 | O3 |
| 2023 | 30 | 50 | 0 | 67 | O3 |
| 2024 | 30 | 54 | 0 | 87 | O3 |
| 2025cleanest | 30 | 47 | 0 | 77 | O3 |
What September air means in Colorado Springs
A typical September day in Colorado Springs is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of September days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
September's median AQI of 51 is above Colorado Springs's whole-year median of 46, making it one of the area's dirtier periods. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Colorado Springs runs above the national September norm; 1.9% of its September days topped AQI 100 versus 2.7% nationally (about the same).
September is part of Colorado Springs's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Colorado Springs
The latest EPA AirNow observation puts Colorado Springs's AQI at 41 (O3). The figures above are multi-year month statistics, not today's reading.
View current Colorado Springs air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Colorado Springs, CO), 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.