Metro area air quality · 2025

York-Hanover, PA

Median AQI 45 (Good). 59.5% of monitored days rated Good across this metro's EPA monitoring network.

45
Median AQI
59.5%
Good-air days
0
Unhealthy days
24%
Cleaner than US metros

York-Hanover, PA posted a 2025 median AQI of 45 (Good) with 59.5% Good days

According to the U.S. EPA Air Quality System, the York-Hanover, PA CBSA recorded a median AQI of 45 across 365 monitored days in 2025, with 59.5% 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 York-Hanover, PA CBSA's 59.5% Good-day share places it cleaner than 24% of US metros in 2025.
Closest median-AQI peer
Akron, OH (61.6% Good, median AQI 45) is the closest nationwide median-AQI peer to York-Hanover, PA.
2020–2025 Good-day shift
York-Hanover, PA's Good-day share moved -0.4 points from 2020 to 2025 (median AQI -1).
Median AQI
Median AQI: 45

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

The verdict

York-Hanover, PA lands in the lower Good-day tercile (59.5% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, among the more polluted US metros, with a median AQI of 45 and 59.5% of 365 monitored days in the Good band.

45
median AQI · Good
59.5%
days rated Good
24%
cleaner than US metros
116
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

2024 → 2025
  • York-Hanover, PA metro's Good-day share fell from 65.8% to 59.9% between the 2024 and 2025 EPA annual releases, a change of -5.8 percentage points.
  • York-Hanover, PA metro's peak single-day AQI rose from 101 to 116 between the 2024 and 2025 EPA annual releases, a change of +15 points.

Compared against 365 monitored days in 2024 and 362 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

York-Hanover, PA lands in the lower Good-day tercile (59.5% Good), a thinner clean-air share than most CBSA peers here. Signature read: 59.5% 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 45 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 217 Good (59%), 145 Moderate (40%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 67; the highest single-day reading hit 116 (USG).

Across 2020–2025, Good-day share shifted -0.4 points and median AQI moved -1 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Akron, OH (61.6% good, AQI 45); Ardmore, OK (67.9% good, AQI 45); Asheville, NC (69.9% good, AQI 45).

Health effects of air pollution →

Air Quality Summary

Median AQI

45

Good

Good Days

59.5%

217 of 365 days

Max AQI

116

USG

Health Grade

Moderate

90th pct: 67

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

217

59%

Moderate

145

40%

USG

3

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The York-Hanover, PA metro area's air quality is rated Moderate based on 59.5% 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 York-Hanover, PA metro compare?

How York-Hanover, PA compares

Good-day share worse than typical
York-Hanover, PA 59.5%
Akron, OH 61.6%
Typical US metro 70.6%
Median AQI worse than typical
York-Hanover, PA 45
Akron, OH 45
Typical US metro 41
Unhealthy days / yr better than typical
York-Hanover, PA 0
Akron, OH 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the York-Hanover, PA metro. Highest Good-day share: 2024 (65.8%, 240 of 365 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 221 145 0 46
2021 168 187 0 51
2022 205 159 0 47
2023 198 150 3 48
2024 240 125 0 44
2025 217 145 0 45

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near York-Hanover, PA (45).

Akron, OH

Median AQI 45 · 61.6% Good-day share

45

Ardmore, OK

Median AQI 45 · 67.9% Good-day share

45

Asheville, NC

Median AQI 45 · 69.9% Good-day share

45

Cheyenne, WY

Median AQI 45 · 75.1% Good-day share

45

Clinton, IA

Median AQI 45 · 59.5% Good-day share

45

Fort Dodge, IA

Median AQI 45 · 59.2% Good-day share

45

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to York-Hanover, PA's 0 (independent of median AQI).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Albany-Schenectady-Troy, NY

0 unhealthy-or-worse days · median AQI 41

41

Frequently Asked Questions

How many unhealthy air days does York-Hanover, PA have? ▼
In 2025, the York-Hanover, PA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 116.
What is the air quality in the York-Hanover, PA metro area? ▼
The York-Hanover, PA metro area has a median Air Quality Index (AQI) of 45, rated "Good." 59.5% of monitored days (217 out of 365) had good air quality in 2025.
Is air quality in York-Hanover, PA getting better or worse? ▼
Air quality in the York-Hanover, PA metro is stable 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 65.8% (240 of 365 days). Lowest qualifying Good-day share: 2021 at 47.3% (168 of 355 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.
How does York-Hanover, PA compare to other metro areas? ▼
The York-Hanover, PA metro has 59.5% good air days. Similar metros: Akron, OH (61.6% good), Ardmore, OK (67.9% good), Asheville, NC (69.9% good).
What is the 90th percentile AQI for York-Hanover, PA? ▼
The 90th percentile AQI for the York-Hanover, PA metro area is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 116 (USG).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for York-Hanover, 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, York-Hanover, PA · 2020–2025