Metro area air quality · 2025

Gettysburg, PA

Median AQI 42 (Good). 74.4% of monitored days rated Good across this metro's EPA monitoring network.

42
Median AQI
74.4%
Good-air days
0
Unhealthy days
56%
Cleaner than US metros

Gettysburg, PA posted a 2025 median AQI of 42 (Good) with 74.4% Good days

According to the U.S. EPA Air Quality System, the Gettysburg, PA CBSA recorded a median AQI of 42 across 351 monitored days in 2025, with 74.4% 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 Gettysburg, PA CBSA's 74.4% Good-day share places it cleaner than 56% of US metros in 2025.
Closest median-AQI peer
Allentown-Bethlehem-Easton, PA-NJ (66.8% Good, median AQI 42) is the closest nationwide median-AQI peer to Gettysburg, PA.
2020–2025 Good-day shift
Gettysburg, PA's Good-day share moved -2.1 points from 2020 to 2025 (median AQI +0).
Median AQI
Median AQI: 42

Aggregated from EPA Air Quality System (2025), 351 monitored days. EPA AQS →

The verdict

Gettysburg, PA's Good-day share (74.4%) 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 42 and 74.4% of 351 monitored days in the Good band.

42
median AQI · Good
74.4%
days rated Good
56%
cleaner than US metros
100
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
  • Gettysburg, PA metro's Good-day share rose from 63.6% to 74.4% between the 2024 and 2025 EPA annual releases, a change of +10.7 percentage points.
  • Gettysburg, PA metro's peak single-day AQI fell from 131 to 100 between the 2024 and 2025 EPA annual releases, a change of -31 points.

Compared against 363 monitored days in 2024 and 351 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

Gettysburg, PA's Good-day share (74.4%) sits in the middle CBSA tercile on this extract. Signature read: 74.4% 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 42 over 351 measured days in 2025 (Good / Moderate). The monitored-day split lands at 261 Good (74%), 90 Moderate (26%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 61; the highest single-day reading hit 100 (Moderate).

Across 2020–2025, Good-day share shifted -2.1 points and median AQI moved +0 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Allentown-Bethlehem-Easton, PA-NJ (66.8% good, AQI 42); Amarillo, TX (78.4% good, AQI 42); Carson City, NV (86.2% good, AQI 42).

Understanding AQI →

Air Quality Summary

Median AQI

42

Good

Good Days

74.4%

261 of 351 days

Max AQI

100

Moderate

Health Grade

Moderate

90th pct: 61

AQI Day Breakdown (2025)

Distribution of 351 monitored days across EPA AQI categories.

Good

261

74%

Moderate

90

26%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Gettysburg, PA metro area's air quality is rated Moderate based on 74.4% 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 Gettysburg, PA metro compare?

How Gettysburg, PA compares

Good-day share better than typical
Gettysburg, PA 74.4%
Allentown-Bethlehem-Easton, PA-NJ 66.8%
Typical US metro 70.6%
Median AQI worse than typical
Gettysburg, PA 42
Allentown-Bethlehem-Easton, PA-NJ 42
Typical US metro 41
Unhealthy days / yr better than typical
Gettysburg, PA 0
Allentown-Bethlehem-Easton, PA-NJ 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Gettysburg, PA metro. Highest Good-day share: 2020 (76.5%, 280 of 366 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 280 86 0 42
2021 206 155 0 47
2022 221 144 0 47
2023 188 166 3 50
2024 231 132 0 44
2025 261 90 0 42

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Gettysburg, PA (42).

Metros with similar unhealthy-day exposure

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

Frequently Asked Questions

How many unhealthy air days does Gettysburg, PA have?
In 2025, the Gettysburg, PA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 100.
What is the air quality in the Gettysburg, PA metro area?
The Gettysburg, PA metro area has a median Air Quality Index (AQI) of 42, rated "Good." 74.4% of monitored days (261 out of 351) had good air quality in 2025.
Is air quality in Gettysburg, PA getting better or worse?
Air quality in the Gettysburg, 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: 2020 at 76.5% (280 of 366 days). Lowest qualifying Good-day share: 2023 at 52.7% (188 of 357 days).
What does AQI 42 mean for health?
An AQI of 42 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 Gettysburg, PA compare to other metro areas?
The Gettysburg, PA metro has 74.4% good air days. Similar metros: Allentown-Bethlehem-Easton, PA-NJ (66.8% good), Amarillo, TX (78.4% good), Carson City, NV (86.2% good).
What is the 90th percentile AQI for Gettysburg, PA?
The 90th percentile AQI for the Gettysburg, PA metro area is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 100 (Moderate).

Data Sources

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