Metro area air quality · 2025

Washington-Arlington-Alexandria, DC-VA-MD-WV

Median AQI 47 (Good). 59.5% of monitored days rated Good across this metro's EPA monitoring network.

47
Median AQI
59.5%
Good-air days
2
Unhealthy days
24%
Cleaner than US metros

Washington-Arlington-Alexandria, DC-VA-MD-WV posted a 2025 median AQI of 47 (Good) with 59.5% Good days

According to the U.S. EPA Air Quality System, the Washington-Arlington-Alexandria, DC-VA-MD-WV CBSA recorded a median AQI of 47 across 365 monitored days in 2025, with 59.5% rated Good and 2 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 Washington-Arlington-Alexandria, DC-VA-MD-WV CBSA's 59.5% Good-day share places it cleaner than 24% of US metros in 2025.
Closest median-AQI peer
Charleston-North Charleston, SC (60.3% Good, median AQI 47) is the closest nationwide median-AQI peer to Washington-Arlington-Alexandria, DC-VA-MD-WV.
2020–2025 Good-day shift
Washington-Arlington-Alexandria, DC-VA-MD-WV's Good-day share moved +1.5 points from 2020 to 2025 (median AQI +0).
Median AQI
Median AQI: 47

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

The verdict

The Washington-Arlington-Alexandria, DC-VA-MD-WV metro runs good on the EPA scale, among the more polluted US metros, a median AQI of 47 with 59.5% of 365 monitored days in the Good band.

47
median AQI · Good
59.5%
days rated Good
24%
cleaner than US metros
185
worst single reading

2 days reached Unhealthy or worse across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Washington-Arlington-Alexandria, DC-VA-MD-WV metro's peak single-day AQI rose from 133 to 185 between the 2024 and 2025 EPA annual releases, a change of +52 points.
  • Washington-Arlington-Alexandria, DC-VA-MD-WV metro's Good-day share rose from 55.6% to 60.3% between the 2024 and 2025 EPA annual releases, a change of +4.7 percentage points.
  • Washington-Arlington-Alexandria, DC-VA-MD-WV metro's Unhealthy-category days rose from 0 to 2 between the 2024 and 2025 EPA annual releases, a change of +2 days.

Compared against 358 monitored days in 2024 and 360 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

Insights: Washington-Arlington-Alexandria, DC-VA-MD-WV metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 47 over 365 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 217 Good days (59%), 141 Moderate (39%), and 5 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 66 while the highest single-day reading hit 185 (Unhealthy). Metro residents averaged roughly 17.8 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +1.5 points and the median AQI moved +0 points, which classifies the multi-year trajectory as stable. The annual record contains 2 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include Charleston-North Charleston, SC (60.3% good, AQI 47); Columbia, SC (58.1% good, AQI 47); Corsicana, TX (59.2% good, AQI 47).

Air Quality Summary

Median AQI

47

Good

Good Days

59.5%

217 of 365 days

Max AQI

185

Unhealthy

Health Grade

Moderate

90th pct: 66

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

217

59%

Moderate

141

39%

USG

5

1%

Unhealthy

2

1%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Washington-Arlington-Alexandria, DC-VA-MD-WV metro area's air quality is rated Moderate based on 59.5% good air days. There were 2 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 5 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 185. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Washington-Arlington-Alexandria, DC-VA-MD-WV metro compare?

How Washington-Arlington-Alexandria, DC-VA-MD-WV compares

Good-day share worse than typical
Washington-Arlington-Alexandria, DC-VA-MD-WV 59.5%
Charleston-North Charleston, SC 60.3%
Typical US metro 70.6%
Median AQI worse than typical
Washington-Arlington-Alexandria, DC-VA-MD-WV 47
Charleston-North Charleston, SC 47
Typical US metro 41
Unhealthy days / yr worse than typical
Washington-Arlington-Alexandria, DC-VA-MD-WV 2
Charleston-North Charleston, SC 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Washington-Arlington-Alexandria, DC-VA-MD-WV metro. Highest Good-day share: 2025 (60.3%, 217 of 360 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 214 149 1 47
2021 153 202 1 53
2022 153 208 0 52
2023 158 187 3 52
2024 199 159 0 49
2025 217 141 2 47

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Washington-Arlington-Alexandria, DC-VA-MD-WV (47).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Washington-Arlington-Alexandria, DC-VA-MD-WV's 2 (independent of median AQI).

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Washington-Arlington-Alexandria, DC-VA-MD-WV metro area?
The Washington-Arlington-Alexandria, DC-VA-MD-WV metro area has a median Air Quality Index (AQI) of 47, rated "Good." 59.5% of monitored days (217 out of 365) had good air quality in 2025.
How many unhealthy air days does Washington-Arlington-Alexandria, DC-VA-MD-WV have?
In 2025, the Washington-Arlington-Alexandria, DC-VA-MD-WV metro area recorded 2 unhealthy air days (2 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 185.
Is air quality in Washington-Arlington-Alexandria, DC-VA-MD-WV getting better or worse?
Air quality in the Washington-Arlington-Alexandria, DC-VA-MD-WV 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: 2025 at 60.3% (217 of 360 days). Lowest qualifying Good-day share: 2022 at 42.4% (153 of 361 days).
What does AQI 47 mean for health?
An AQI of 47 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 Washington-Arlington-Alexandria, DC-VA-MD-WV?
The 90th percentile AQI for the Washington-Arlington-Alexandria, DC-VA-MD-WV metro area is 66, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 185 (Unhealthy).
How does Washington-Arlington-Alexandria, DC-VA-MD-WV compare to other metro areas?
The Washington-Arlington-Alexandria, DC-VA-MD-WV metro has 59.5% good air days. Similar metros: Charleston-North Charleston, SC (60.3% good), Columbia, SC (58.1% good), Corsicana, TX (59.2% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. 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 files (metro-level) · 2020–2025

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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.