Metro area air quality · 2024

Chambersburg-Waynesboro, PA

Median AQI 35 (Good). 93.3% of monitored days rated Good across this metro's EPA monitoring network.

35
Median AQI
93.3%
Good-air days
0
Unhealthy days
90%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 327 monitored days. EPA AQS → · NOAA →

Insights: Chambersburg-Waynesboro, PA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 35 over 327 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 305 Good days (93%), 22 Moderate (7%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 49 while the highest single-day reading hit 90 (Moderate). Metro residents averaged roughly 28.0 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -58 and the median AQI moved +3 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 Arkadelphia, AR (93.3% good, AQI 35); Atlantic City-Hammonton, NJ (82.5% good, AQI 35); Augusta-Waterville, ME (84.7% good, AQI 35).

Air Quality Summary

Median AQI

35

Good

Good Days

93.3%

305 of 327 days

Max AQI

90

Moderate

Health Grade

Excellent

90th pct: 49

AQI Day Breakdown (2024)

Distribution of 327 monitored days across EPA AQI categories.

Good

305

93%

Moderate

22

7%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Chambersburg-Waynesboro, PA metro area's air quality is rated Excellent based on 93.3% good air days. No unhealthy air days were recorded in 2024.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Chambersburg-Waynesboro, PA metro compare?

How Chambersburg-Waynesboro, PA compares

Good-day share better than US avg
Chambersburg-Waynesboro, PA 93.3%
Arkadelphia, AR 93.3%
US average 70.2%
Median AQI better than US avg
Chambersburg-Waynesboro, PA 35
Arkadelphia, AR 35
US average 41
Unhealthy days / yr better than US avg
Chambersburg-Waynesboro, PA 0
Arkadelphia, AR 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Chambersburg-Waynesboro, PA metro. Best year: 2020 (363 good days).

Year Good Moderate Unhealthy Median AQI
2020 363 0 0 32
2021 274 14 0 35
2022 225 12 0 39
2023 267 32 0 39
2024 305 22 0 35

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Chambersburg-Waynesboro, PA.

Arkadelphia, AR

AQI 35 · 93.3% good

35

Atlantic City-Hammonton, NJ

AQI 35 · 82.5% good

35

Augusta-Waterville, ME

AQI 35 · 84.7% good

35

Beatrice, NE

AQI 35 · 73.0% good

35

Claremont-Lebanon, NH-VT

AQI 35 · 91.3% good

35

East Stroudsburg, PA

AQI 35 · 91.4% good

35

More Air Quality Data

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All Metro Areas

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Air Quality Guides

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Understanding AQI

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Best & Worst City Air Quality

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Health Effects of Air Pollution

How PM2.5 and ozone exposure affects respiratory and cardiovascular health.

Frequently Asked Questions

What is the air quality in the Chambersburg-Waynesboro, PA metro area? ▼
The Chambersburg-Waynesboro, PA metro area has a median Air Quality Index (AQI) of 35, rated "Good." 93.3% of monitored days (305 out of 327) had good air quality in 2024.
How many unhealthy air days does Chambersburg-Waynesboro, PA have? ▼
In 2024, the Chambersburg-Waynesboro, PA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 90.
Is air quality in Chambersburg-Waynesboro, PA getting better or worse? ▼
Air quality in the Chambersburg-Waynesboro, PA metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 363 good days. Worst year: 2022 with 225 good days.
What does AQI 35 mean for health? ▼
An AQI of 35 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 Chambersburg-Waynesboro, PA? ▼
The 90th percentile AQI for the Chambersburg-Waynesboro, PA metro area is 49, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 90 (Moderate).
How does Chambersburg-Waynesboro, PA compare to other metro areas? ▼
The Chambersburg-Waynesboro, PA metro has 93.3% good air days. Similar metros: Arkadelphia, AR (93.3% good), Atlantic City-Hammonton, NJ (82.5% good), Augusta-Waterville, ME (84.7% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2024. The AQS collects ambient air monitoring data from state, local, and tribal monitoring agencies across the United States.

Metrics: Air Quality Index (AQI) is calculated using EPA-standard breakpoints for six criteria pollutants: PM2.5, PM10, Ozone, NO2, CO, and SO2. Median AQI, max AQI, and 90th percentile AQI are computed from daily measurements. Good days percentage reflects days with AQI 0–50.

Coverage: 501 metro areas (Core Based Statistical Areas). Only metros with active monitoring stations are included. Unmonitored areas are not represented.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA, AirNow / AQS Air Quality Index readings and pollutant concentrations · 2025