New Castle, PA

EPA AQS → · NOAA →

Metro area air quality from EPA Air Quality System (2024). 31 days monitored. Median AQI: 24 (Good).

Insights: New Castle, PA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 24 over 31 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 31 Good days (100%), 0 Moderate (0%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 29 while the highest single-day reading hit 31 (Good). Metro residents averaged roughly 30.0 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -323 and the median AQI moved -7 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 Aberdeen, SD (85.7% good, AQI 24); Coeur d'Alene, ID (82.0% good, AQI 24); Juneau, AK (85.4% good, AQI 24).

Air Quality Summary

Median AQI

24

Good

Good Days

100.0%

31 of 31 days

Max AQI

31

Good

Health Grade

Excellent

90th pct: 29

AQI Day Breakdown (2024)

Distribution of 31 monitored days across EPA AQI categories.

Good

31

100%

Moderate

0

0%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The New Castle, PA metro area's air quality is rated Excellent based on 100.0% 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.

5-Year Air Quality Trend

Air quality is worsening in the New Castle, PA metro. Best year: 2020 (354 good days).

Year Good Moderate Unhealthy Median AQI
2020 354 9 0 31
2021 259 19 0 31
2022 223 18 0 37
2023 254 12 0 34
2024 31 0 0 24

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to New Castle, PA.

Aberdeen, SD

AQI 24 · 85.7% good

24

Coeur d'Alene, ID

AQI 24 · 82.0% good

24

Juneau, AK

AQI 24 · 85.4% good

24

Prineville, OR

AQI 24 · 77.0% good

24

Albany, OR

AQI 25 · 87.4% good

25

Elko, NV

AQI 23 · 87.1% good

23

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FEMA disaster declarations. Wildfire, flood, and storm history affecting air quality. FEMA.gov →

Air Quality Guides

Learn more about air quality monitoring, pollutants, and health impacts.

Understanding AQI

What each AQI level means and who is most at risk.

Best & Worst City Air Quality

Metro area air quality rankings and what drives urban pollution.

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 New Castle, PA metro area? ▼
The New Castle, PA metro area has a median Air Quality Index (AQI) of 24, rated "Good." 100.0% of monitored days (31 out of 31) had good air quality in 2024.
How many unhealthy air days does New Castle, PA have? ▼
In 2024, the New Castle, PA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 31.
Is air quality in New Castle, PA getting better or worse? ▼
Air quality in the New Castle, PA metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 354 good days. Worst year: 2024 with 31 good days.
What does AQI 24 mean for health? ▼
An AQI of 24 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 New Castle, PA? ▼
The 90th percentile AQI for the New Castle, PA metro area is 29, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 31 (Good).
How does New Castle, PA compare to other metro areas? ▼
The New Castle, PA metro has 100.0% good air days. Similar metros: Aberdeen, SD (85.7% good), Coeur d'Alene, ID (82.0% good), Juneau, AK (85.4% 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