Metro area air quality · 2025

St. George, UT

Median AQI 45 (Good). 71.0% of monitored days rated Good across this metro's EPA monitoring network.

45
Median AQI
71.0%
Good-air days
0
Unhealthy days
46%
Cleaner than US metros

Aggregated from EPA Air Quality System (2025), 304 monitored days. EPA AQS →

The verdict

The St. George, UT metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 45 with 71.0% of 304 monitored days in the Good band.

45
median AQI · Good
71.0%
days rated Good
46%
cleaner than US metros
97
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Insights: St. George, UT metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 45 over 304 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 216 Good days (71%), 88 Moderate (29%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 64 while the highest single-day reading hit 97 (Moderate). Metro residents averaged roughly 21.3 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -60 and the median AQI moved +1 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 Akron, OH (62.2% good, AQI 45); Carson City, NV (79.3% good, AQI 45); Clinton, IA (59.9% good, AQI 45).

Air Quality Summary

Median AQI

45

Good

Good Days

71.0%

216 of 304 days

Max AQI

97

Moderate

Health Grade

Moderate

90th pct: 64

AQI Day Breakdown (2025)

Distribution of 304 monitored days across EPA AQI categories.

Good

216

71%

Moderate

88

29%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The St. George, UT metro area's air quality is rated Moderate based on 71.0% 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 St. George, UT metro compare?

How St. George, UT compares

Good-day share about average
St. George, UT 71.0%
Akron, OH 62.2%
US average 71.3%
Median AQI worse than US avg
St. George, UT 45
Akron, OH 45
US average 41
Unhealthy days / yr better than US avg
St. George, UT 0
Akron, OH 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the St. George, UT metro. Best year: 2023 (291 good days).

Year Good Moderate Unhealthy Median AQI
2020 276 87 0 44
2021 256 106 1 45
2022 288 77 0 44
2023 291 74 0 43
2024 278 86 0 44
2025 216 88 0 45

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to St. George, UT.

Akron, OH

AQI 45 · 62.2% good

45

Carson City, NV

AQI 45 · 79.3% good

45

Clinton, IA

AQI 45 · 59.9% good

45

Davenport-Moline-Rock Island, IA-IL

AQI 45 · 58.4% good

45

Española, NM

AQI 45 · 79.9% good

45

Gadsden, AL

AQI 45 · 63.5% good

45

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the St. George, UT metro area? ▼
The St. George, UT metro area has a median Air Quality Index (AQI) of 45, rated "Good." 71.0% of monitored days (216 out of 304) had good air quality in 2025.
How many unhealthy air days does St. George, UT have? ▼
In 2025, the St. George, UT metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is air quality in St. George, UT getting better or worse? ▼
Air quality in the St. George, UT metro is worsening based on 5-year trends (2020-2025). Best year: 2023 with 291 good days. Worst year: 2025 with 216 good days.
What does AQI 45 mean for health? ▼
An AQI of 45 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for St. George, UT? ▼
The 90th percentile AQI for the St. George, UT metro area is 64, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 97 (Moderate).
How does St. George, UT compare to other metro areas? ▼
The St. George, UT metro has 71.0% good air days. Similar metros: Akron, OH (62.2% good), Carson City, NV (79.3% good), Clinton, IA (59.9% good).

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.