Metro area air quality · 2025

Harrisburg-Carlisle, PA

Median AQI 44 (Good). 61.4% of monitored days rated Good across this metro's EPA monitoring network.

44
Median AQI
61.4%
Good-air days
0
Unhealthy days
27%
Cleaner than US metros

Harrisburg-Carlisle, PA posted a 2025 median AQI of 44 (Good) with 61.4% Good days

According to the U.S. EPA Air Quality System, the Harrisburg-Carlisle, PA CBSA recorded a median AQI of 44 across 365 monitored days in 2025, with 61.4% 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 Harrisburg-Carlisle, PA CBSA's 61.4% Good-day share places it cleaner than 27% of US metros in 2025.
Closest median-AQI peer
Bartlesville, OK (68.0% Good, median AQI 44) is the closest nationwide median-AQI peer to Harrisburg-Carlisle, PA.
2020–2025 Good-day shift
Harrisburg-Carlisle, PA's Good-day share moved +3.7 points from 2020 to 2025 (median AQI -4).
Median AQI
Median AQI: 44

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

The verdict

Harrisburg-Carlisle, PA lands in the lower Good-day tercile (61.4% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 44 and 61.4% of 365 monitored days in the Good band.

44
median AQI · Good
61.4%
days rated Good
27%
cleaner than US metros
101
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
  • Harrisburg-Carlisle, PA metro's Good-day share rose from 55.2% to 61.5% between the 2024 and 2025 EPA annual releases, a change of +6.3 percentage points.
  • Harrisburg-Carlisle, PA metro's median AQI fell from 48 to 44 between the 2024 and 2025 EPA annual releases, a change of -4 points.

Compared against 364 monitored days in 2024 and 364 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

Harrisburg-Carlisle, PA lands in the lower Good-day tercile (61.4% Good), a thinner clean-air share than most CBSA peers here. Signature read: 61.4% 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 44 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 224 Good (61%), 140 Moderate (38%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 66; the highest single-day reading hit 101 (USG).

Across 2020–2025, Good-day share shifted +3.7 points and median AQI moved -4 (improving). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Bartlesville, OK (68.0% good, AQI 44); Berlin, NH-VT (81.5% good, AQI 44); Bloomington, IL (66.0% good, AQI 44).

Health effects of air pollution →

Air Quality Summary

Median AQI

44

Good

Good Days

61.4%

224 of 365 days

Max AQI

101

USG

Health Grade

Moderate

90th pct: 66

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

224

61%

Moderate

140

38%

USG

1

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Harrisburg-Carlisle, PA metro area's air quality is rated Moderate based on 61.4% 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 Harrisburg-Carlisle, PA metro compare?

How Harrisburg-Carlisle, PA compares

Good-day share worse than typical
Harrisburg-Carlisle, PA 61.4%
Bartlesville, OK 68.0%
Typical US metro 70.6%
Median AQI worse than typical
Harrisburg-Carlisle, PA 44
Bartlesville, OK 44
Typical US metro 41
Unhealthy days / yr better than typical
Harrisburg-Carlisle, PA 0
Bartlesville, OK 1
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Harrisburg-Carlisle, PA metro. Highest Good-day share: 2025 (61.5%, 224 of 364 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 210 153 0 48
2021 157 206 0 52
2022 185 177 0 50
2023 164 189 3 52
2024 201 163 0 48
2025 224 140 0 44

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Harrisburg-Carlisle, PA (44).

Metros with similar unhealthy-day exposure

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

Frequently Asked Questions

How many unhealthy air days does Harrisburg-Carlisle, PA have?
In 2025, the Harrisburg-Carlisle, 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 Harrisburg-Carlisle, PA metro area?
The Harrisburg-Carlisle, PA metro area has a median Air Quality Index (AQI) of 44, rated "Good." 61.4% of monitored days (224 out of 365) had good air quality in 2025.
Is air quality in Harrisburg-Carlisle, PA getting better or worse?
Air quality in the Harrisburg-Carlisle, PA metro is improving across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2025 at 61.5% (224 of 364 days). Lowest qualifying Good-day share: 2021 at 43.3% (157 of 363 days).
What does AQI 44 mean for health?
An AQI of 44 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 Harrisburg-Carlisle, PA compare to other metro areas?
The Harrisburg-Carlisle, PA metro has 61.4% good air days. Similar metros: Bartlesville, OK (68.0% good), Berlin, NH-VT (81.5% good), Bloomington, IL (66.0% good).
What is the 90th percentile AQI for Harrisburg-Carlisle, PA?
The 90th percentile AQI for the Harrisburg-Carlisle, PA metro area is 66, 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 Harrisburg-Carlisle, PA, 2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Harrisburg-Carlisle, PA · 2020–2025