Metro area air quality · 2024

Charleston, WV

Median AQI 40 (Good). 77.8% of monitored days rated Good across this metro's EPA monitoring network.

40
Median AQI
77.8%
Good-air days
0
Unhealthy days
59%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 364 monitored days. EPA AQS → · NOAA →

Insights: Charleston, WV metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 40 over 364 measured days in 2024, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 283 Good days (78%), 81 Moderate (22%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 57 while the highest single-day reading hit 90 (Moderate). Metro residents averaged roughly 23.3 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -4 and the median AQI moved -1 points, which classifies the multi-year trajectory as stable. 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 Bismarck, ND (73.0% good, AQI 40); Cambridge, MD (80.3% good, AQI 40); Charlottesville, VA (78.9% good, AQI 40).

Air Quality Summary

Median AQI

40

Good

Good Days

77.8%

283 of 364 days

Max AQI

90

Moderate

Health Grade

Good

90th pct: 57

AQI Day Breakdown (2024)

Distribution of 364 monitored days across EPA AQI categories.

Good

283

78%

Moderate

81

22%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Charleston, WV metro area's air quality is rated Good based on 77.8% 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 Charleston, WV metro compare?

How Charleston, WV compares

Good-day share better than US avg
Charleston, WV 77.8%
Bismarck, ND 73.0%
US average 70.2%
Median AQI better than US avg
Charleston, WV 40
Bismarck, ND 40
US average 41
Unhealthy days / yr better than US avg
Charleston, WV 0
Bismarck, ND 2
US average 1

5-Year Air Quality Trend

Air quality is stable in the Charleston, WV metro. Best year: 2020 (287 good days).

Year Good Moderate Unhealthy Median AQI
2020 287 79 0 41
2021 239 126 0 44
2022 253 100 0 41
2023 254 106 1 42
2024 283 81 0 40

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Charleston, WV.

Bismarck, ND

AQI 40 · 73.0% good

40

Cambridge, MD

AQI 40 · 80.3% good

40

Charlottesville, VA

AQI 40 · 78.9% good

40

Daphne-Fairhope-Foley, AL

AQI 40 · 78.3% good

40

Hartford-West Hartford-East Hartford, CT

AQI 40 · 75.4% good

40

Jefferson City, MO

AQI 40 · 95.0% good

40

More Air Quality Data

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Worst Air Quality

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All Metro Areas

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Best and Worst City Air

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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 Charleston, WV metro area? ▼
The Charleston, WV metro area has a median Air Quality Index (AQI) of 40, rated "Good." 77.8% of monitored days (283 out of 364) had good air quality in 2024.
How many unhealthy air days does Charleston, WV have? ▼
In 2024, the Charleston, WV metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 90.
Is air quality in Charleston, WV getting better or worse? ▼
Air quality in the Charleston, WV metro is stable based on 5-year trends (2020-2024). Best year: 2020 with 287 good days. Worst year: 2021 with 239 good days.
What does AQI 40 mean for health? ▼
An AQI of 40 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 Charleston, WV? ▼
The 90th percentile AQI for the Charleston, WV metro area is 57, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 90 (Moderate).
How does Charleston, WV compare to other metro areas? ▼
The Charleston, WV metro has 77.8% good air days. Similar metros: Bismarck, ND (73.0% good), Cambridge, MD (80.3% good), Charlottesville, VA (78.9% 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