Metro area air quality · 2025

State College, PA

Median AQI 43 (Good). 71.5% of monitored days rated Good across this metro's EPA monitoring network.

43
Median AQI
71.5%
Good-air days
0
Unhealthy days
47%
Cleaner than US metros

Aggregated from EPA Air Quality System (2025), 242 monitored days. EPA AQS →

The verdict

The State College, PA metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 43 with 71.5% of 242 monitored days in the Good band.

43
median AQI · Good
71.5%
days rated Good
47%
cleaner than US metros
101
worst single reading

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

Insights: State College, PA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 43 over 242 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 173 Good days (71%), 68 Moderate (28%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 63 while the highest single-day reading hit 101 (USG). Metro residents averaged roughly 21.4 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -114 and the median AQI moved +2 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 Allentown-Bethlehem-Easton, PA-NJ (65.6% good, AQI 43); Amarillo, TX (75.7% good, AQI 43); Ashtabula, OH (81.2% good, AQI 43).

Air Quality Summary

Median AQI

43

Good

Good Days

71.5%

173 of 242 days

Max AQI

101

USG

Health Grade

Moderate

90th pct: 63

AQI Day Breakdown (2025)

Distribution of 242 monitored days across EPA AQI categories.

Good

173

71%

Moderate

68

28%

USG

1

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The State College, PA metro area's air quality is rated Moderate based on 71.5% 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 State College, PA metro compare?

How State College, PA compares

Good-day share about average
State College, PA 71.5%
Allentown-Bethlehem-Easton, PA-NJ 65.6%
US average 71.3%
Median AQI worse than US avg
State College, PA 43
Allentown-Bethlehem-Easton, PA-NJ 43
US average 41
Unhealthy days / yr better than US avg
State College, PA 0
Allentown-Bethlehem-Easton, PA-NJ 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the State College, PA metro. Best year: 2024 (287 good days).

Year Good Moderate Unhealthy Median AQI
2020 287 79 0 41
2021 241 123 0 43
2022 240 125 0 44
2023 239 118 5 45
2024 287 79 0 40
2025 173 68 0 43

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to State College, PA.

Allentown-Bethlehem-Easton, PA-NJ

AQI 43 · 65.6% good

43

Amarillo, TX

AQI 43 · 75.7% good

43

Ashtabula, OH

AQI 43 · 81.2% good

43

College Station-Bryan, TX

AQI 43 · 63.4% good

43

Fallon, NV

AQI 43 · 81.0% good

43

Gillette, WY

AQI 43 · 77.3% good

43

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 State College, PA metro area? ▼
The State College, PA metro area has a median Air Quality Index (AQI) of 43, rated "Good." 71.5% of monitored days (173 out of 242) had good air quality in 2025.
How many unhealthy air days does State College, PA have? ▼
In 2025, the State College, PA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 101.
Is air quality in State College, PA getting better or worse? ▼
Air quality in the State College, PA metro is worsening based on 5-year trends (2020-2025). Best year: 2024 with 287 good days. Worst year: 2025 with 173 good days.
What does AQI 43 mean for health? ▼
An AQI of 43 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 State College, PA? ▼
The 90th percentile AQI for the State College, PA metro area is 63, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 101 (USG).
How does State College, PA compare to other metro areas? ▼
The State College, PA metro has 71.5% good air days. Similar metros: Allentown-Bethlehem-Easton, PA-NJ (65.6% good), Amarillo, TX (75.7% good), Ashtabula, OH (81.2% 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.