Fort Collins Air Quality in 2024
In 2024, Fort Collins's air quality (Fort Collins, CO area) had a median daily AQI of 54 (Moderate) across 366 monitored days. 23 days (6.3%) reached Unhealthy for Sensitive Groups or worse, 156 were Good, and the year's peak AQI was 161 (Unhealthy). Ground-level ozone set the daily AQI on 300 of those days. The cleanest month of 2024 was January (median AQI 44, 0 days above 100) and the worst was July (median 97, 15 days above 100, peak 161).
- Good: 42.6%
- Moderate: 51.1%
- Unhealthy for Sensitive Groups: 5.7%
- Unhealthy or worse: 0.5%
Reduce Indoor Ozone in Fort Collins
Today's main pollutant in Fort Collins is ground-level ozone (AQI 36). 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 was Fort Collins's air quality in 2024?
Moderate on a typical day: median AQI 54, with 23 days above AQI 100 out of 366 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2024: 161 (Unhealthy).
- ✓Ground-level ozone was the main pollutant on 300 days.
- ✓Cleanest month: January; worst: July.
Frequently asked questions
What was the average AQI in Fort Collins in 2024?▾
EPA's Air Quality System puts Fort Collins's (Fort Collins, CO) median daily AQI for 2024 at 54, which is Moderate. 23 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 161.
Which month had the worst air quality in Fort Collins in 2024?▾
The cleanest month of 2024 was January (median AQI 44, 0 days above 100) and the worst was July (median 97, 15 days above 100, peak 161).
Was 2024 a good or bad year for Fort Collins's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 6th cleanest by days above AQI 100. 2024's median of 54 is above the area's typical annual median of 51.
Fort Collins month by month in 2024
Fort Collins air quality month by month, 2024 (Fort Collins, CO, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| Januarycleanest | 31 | 44 | 0 | 77 | O3 |
| February | 29 | 47 | 0 | 55 | O3 |
| March | 31 | 48 | 0 | 74 | O3 |
| April | 30 | 60 | 0 | 93 | O3 |
| May | 31 | 67 | 0 | 90 | O3 |
| June | 30 | 67 | 2 | 112 | O3 |
| Julyworst | 31 | 97 | 15 | 161 | O3 |
| August | 31 | 61 | 6 | 147 | O3 |
| September | 30 | 64 | 0 | 90 | O3 |
| October | 31 | 55 | 0 | 78 | PM2.5 |
| November | 30 | 47 | 0 | 64 | O3 |
| December | 31 | 46 | 0 | 58 | O3 |
How 2024 compares
Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 6th cleanest by days above AQI 100.
2024's median of 54 is above the area's typical annual median of 51.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Fort Collins
The latest EPA AirNow observation puts Fort Collins's AQI at 36 (O3). The figures above are multi-year annual statistics, not today's reading.
View current Fort Collins air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Fort Collins, 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.