Metro area air quality · 2025
Greeley, CO
Median AQI 52 (Moderate). 44.7% of monitored days rated Good across this metro's EPA monitoring network.
- 52
- Median AQI
- 44.7%
- Good-air days
- 0
- Unhealthy days
- 10%
- Cleaner than US metros
Greeley, CO posted a 2025 median AQI of 52 (Moderate) with 44.7% Good days
According to the U.S. EPA Air Quality System, the Greeley, CO CBSA recorded a median AQI of 52 across 365 monitored days in 2025, with 44.7% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US metros
- The Greeley, CO CBSA's 44.7% Good-day share places it cleaner than 10% of US metros in 2025.
- Closest median-AQI peer
- Augusta-Richmond County, GA-SC (46.0% Good, median AQI 52) is the closest nationwide median-AQI peer to Greeley, CO.
- 2020–2025 Good-day shift
- Greeley, CO's Good-day share moved -1.6 points from 2020 to 2025 (median AQI +0).
- Median AQI
- Median AQI: 52
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
Greeley, CO lands in the lower Good-day tercile (44.7% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs moderate, among the more polluted US metros, with a median AQI of 52 and 44.7% of 365 monitored days in the Good band.
- 52
- median AQI · Moderate
- 44.7%
- days rated Good
- 10%
- cleaner than US metros
- 119
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Greeley, CO metro's peak single-day AQI fell from 164 to 119 between the 2024 and 2025 EPA annual releases, a change of -45 points.
- Greeley, CO metro's Good-day share rose from 42.9% to 45.4% between the 2024 and 2025 EPA annual releases, a change of +2.5 percentage points.
- Greeley, CO metro's Unhealthy-category days fell from 2 to 0 between the 2024 and 2025 EPA annual releases, a change of -2 days.
Greeley, CO lands in the lower Good-day tercile (44.7% Good), a thinner clean-air share than most CBSA peers here. Signature read: 44.7% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 52 over 365 measured days in 2025 (Moderate / Poor). The monitored-day split lands at 163 Good (45%), 196 Moderate (54%), and 6 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 80; the highest single-day reading hit 119 (USG).
Across 2020–2025, Good-day share shifted -1.6 points and median AQI moved +0 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Augusta-Richmond County, GA-SC (46.0% good, AQI 52); Beaumont-Port Arthur, TX (41.4% good, AQI 52); Birmingham-Hoover, AL (43.0% good, AQI 52).
Air Quality Summary
Median AQI
52
Moderate
Good Days
44.7%
163 of 365 days
Max AQI
119
USG
Health Grade
Poor
90th pct: 80
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
163
45%
Moderate
196
54%
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 44.7% 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 stable in the Greeley, CO metro. Highest Good-day share: 2022 (47.9%, 170 of 355 monitored 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 | 163 | 196 | 0 | 52 | 119 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Greeley, CO (52).
Augusta-Richmond County, GA-SC
Median AQI 52 · 46.0% Good-day share
Beaumont-Port Arthur, TX
Median AQI 52 · 41.4% Good-day share
Birmingham-Hoover, AL
Median AQI 52 · 43.0% Good-day share
Charlotte-Concord-Gastonia, NC-SC
Median AQI 52 · 46.0% Good-day share
El Dorado, AR
Median AQI 52 · 41.8% Good-day share
Grand Rapids-Wyoming, MI
Median AQI 52 · 41.9% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Greeley, CO's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Frequently Asked Questions
How many unhealthy air days does Greeley, CO have? ▼
What is the air quality in the Greeley, CO metro area? ▼
Is air quality in Greeley, CO getting better or worse? ▼
What does AQI 52 mean for health? ▼
How does Greeley, CO compare to other metro areas? ▼
What is the 90th percentile AQI for Greeley, CO? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Greeley, CO, 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, Greeley, CO · 2020–2025