Metro area air quality · 2025

State College, PA

Median AQI 41 (Good). 74.3% of monitored days rated Good across this metro's EPA monitoring network.

Compiled by PlainAirData · August 23, 2026

41
Median AQI: 74.3%
Good-air days: 0
Unhealthy days: 54%
Cleaner than US metros

State College, PA posted a 2025 median AQI of 41 (Good) with 74.3% Good days

According to the U.S. EPA Air Quality System, the State College, PA CBSA recorded a median AQI of 41 across 365 monitored days in 2025, with 74.3% 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 State College, PA CBSA's 74.3% Good-day share places it cleaner than 54% of US metros in 2025.
Closest median-AQI peer: Adrian, MI (69.3% Good, median AQI 41) is the closest nationwide median-AQI peer to State College, PA.
2020–2025 Good-day shift: State College, PA's Good-day share moved -4.0 points from 2020 to 2025 (median AQI +0).
Median AQI: Median AQI: 41

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

State College, PA's Good-day share (74.3%) sits in the middle CBSA tercile on this extract. On the EPA scale the metro runs good, cleaner than the median US metro, with a median AQI of 41 and 74.3% of 365 monitored days in the Good band.

41
median AQI · Good: 74.3%
days rated Good: 54%
cleaner than US metros: 101
worst single reading

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

State College, PA metro's Good-day share fell from 78.4% to 74.5% between the 2024 and 2025 EPA annual releases, a change of -4.0 percentage points.

State College, PA's Good-day share (74.3%) sits in the middle CBSA tercile on this extract. Signature read: 74.3% Good-day share (mid tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 41 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 271 Good (74%), 93 Moderate (25%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 58; the highest single-day reading hit 101 (USG).

Across 2020–2025, Good-day share shifted -4.0 points and median AQI moved +0 (worsening). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Adrian, MI (69.3% good, AQI 41); Albany-Schenectady-Troy, NY (67.7% good, AQI 41); Ann Arbor, MI (69.3% good, AQI 41).

Understanding AQI →

Air Quality Summary

Median AQI

Good

Good Days

74.3%

271 of 365 days

Max AQI

101

USG

Health Grade

Moderate

90th pct: 58

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

271

74%

Moderate

25%

USG

Unhealthy

Very Unhealthy

Hazardous

Health Impact Assessment

Moderate

The State College, PA metro area's air quality is rated Moderate based on 74.3% 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

Compare against

Good-day share better than typical

State College, PA 74.3%

Adrian, MI 69.3%

Typical US metro 70.6%

Median AQI about typical

State College, PA 41

Adrian, MI 41

Typical US metro 41

Unhealthy days / yr better than typical

State College, PA 0

Adrian, MI 0

Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the State College, PA metro. Highest Good-day share: 2024 (78.4%, 287 of 366 monitored days).

Year	Good	Moderate	Unhealthy	Median AQI	Max AQI
2020	287	79	0	41	91
2021	241	123	0	43	114
2022	240	125	0	44	89
2023	239	118	5	45	199
2024	287	79	0	40	97
2025	271	93	0	41	101

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near State College, PA (41).

Adrian, MI

Median AQI 41 · 69.3% Good-day share

Albany-Schenectady-Troy, NY

Median AQI 41 · 67.7% Good-day share

Ann Arbor, MI

Median AQI 41 · 69.3% Good-day share

Bowling Green, KY

Median AQI 41 · 75.6% Good-day share

Brunswick, GA

Median AQI 41 · 74.3% Good-day share

Decatur, AL

Median AQI 41 · 78.4% Good-day share

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to State College, PA'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

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

Alexandria, LA

0 unhealthy-or-worse days · median AQI 37

Frequently Asked Questions

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.

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 41, rated "Good." 74.3% of monitored days (271 out of 365) had good air quality in 2025.

Is air quality in State College, PA getting better or worse? ▼

Air quality in the State College, PA metro is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 78.4% (287 of 366 days). Lowest qualifying Good-day share: 2022 at 65.8% (240 of 365 days).

What does AQI 41 mean for health? ▼

An AQI of 41 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.

How does State College, PA compare to other metro areas? ▼

The State College, PA metro has 74.3% good air days. Similar metros: Adrian, MI (69.3% good), Albany-Schenectady-Troy, NY (67.7% good), Ann Arbor, MI (69.3% good).

What is the 90th percentile AQI for State College, PA? ▼

The 90th percentile AQI for the State College, PA metro area is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 101 (USG).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for State College, PA, 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, State College, PA · 2020–2025 Accessed 2026-07-06