Metro area air quality · 2025
Greeley, CO
Median AQI 52 (Moderate). 42.7% of monitored days rated Good across this metro's EPA monitoring network.
- 52
- Median AQI
- 42.7%
- Good-air days
- 0
- Unhealthy days
- 7%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2025), 274 monitored days. EPA AQS →
The verdict
The Greeley, CO metro runs moderate on the EPA scale, among the more polluted US metros, a median AQI of 52 with 42.7% of 274 monitored days in the Good band.
- 52
- median AQI · Moderate
- 42.7%
- days rated Good
- 7%
- cleaner than US metros
- 119
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Insights: Greeley, CO metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 52 over 274 measured days in 2025, which corresponds to a Moderate band and a Poor metro-wide health grade. The monitored-day split lands at 117 Good days (43%), 151 Moderate (55%), and 6 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 84 while the highest single-day reading hit 119 (USG). Metro residents averaged roughly 12.8 clean-air days per 30-day window across the reporting year.
Across the 2020–2025 trend window, good days shifted by -49 and the median AQI moved +0 points, which classifies the multi-year trajectory as worsening. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Atlanta-Sandy Springs-Roswell, GA (45.3% good, AQI 52); El Dorado, AR (44.0% good, AQI 52); Jackson, MS (43.4% good, AQI 52).
Air Quality Summary
Median AQI
52
Moderate
Good Days
42.7%
117 of 274 days
Max AQI
119
USG
Health Grade
Poor
90th pct: 84
AQI Day Breakdown (2025)
Distribution of 274 monitored days across EPA AQI categories.
Good
117
43%
Moderate
151
55%
USG
6
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Greeley, CO metro area's air quality is rated Poor based on 42.7% good air days. No unhealthy air days were recorded in 2025.
Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.
How does the Greeley, CO metro compare?
How Greeley, CO compares
5-Year Air Quality Trend
Air quality is worsening in the Greeley, CO metro. Best year: 2022 (170 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 166 | 187 | 0 | 52 | 140 |
| 2021 | 156 | 169 | 1 | 54 | 154 |
| 2022 | 170 | 185 | 0 | 51 | 133 |
| 2023 | 146 | 214 | 1 | 55 | 162 |
| 2024 | 149 | 196 | 2 | 54 | 164 |
| 2025 | 117 | 151 | 0 | 52 | 119 |
Metros with Similar Air Quality
Metro areas across the US with a similar median AQI to Greeley, CO.
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Worst Air Quality
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All Metro Areas
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Air Quality Guides
Frequently Asked Questions
What is the air quality in the Greeley, CO metro area? ▼
How many unhealthy air days does Greeley, CO have? ▼
Is air quality in Greeley, CO getting better or worse? ▼
What does AQI 52 mean for health? ▼
What is the 90th percentile AQI for Greeley, CO? ▼
How does Greeley, CO compare to other metro areas? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025
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.