Metro area air quality · 2025

Wilmington, OH

Median AQI 41 (Good). 83.1% of monitored days rated Good across this metro's EPA monitoring network.

41
Median AQI
83.1%
Good-air days
0
Unhealthy days
73%
Cleaner than US metros

Wilmington, OH posted a 2025 median AQI of 41 (Good) with 83.1% Good days

According to the U.S. EPA Air Quality System, the Wilmington, OH CBSA recorded a median AQI of 41 across 243 monitored days in 2025, with 83.1% 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 Wilmington, OH CBSA's 83.1% Good-day share places it cleaner than 73% of US metros in 2025.
Closest median-AQI peer
Adrian, MI (69.3% Good, median AQI 41) is the closest nationwide median-AQI peer to Wilmington, OH.
2020–2025 Good-day shift
Wilmington, OH's Good-day share moved -5.4 points from 2020 to 2025 (median AQI +2).
Median AQI
Median AQI: 41

Aggregated from EPA Air Quality System (2025), 243 monitored days. EPA AQS →

The verdict

The Wilmington, OH metro runs good on the EPA scale, cleaner than the median US metro, a median AQI of 41 with 83.1% of 243 monitored days in the Good band.

41
median AQI · Good
83.1%
days rated Good
73%
cleaner than US metros
112
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
  • Wilmington, OH metro's Good-day share rose from 74.6% to 84.2% between the 2024 and 2025 EPA annual releases, a change of +9.6 percentage points.
  • Wilmington, OH metro's median AQI fell from 44 to 41 between the 2024 and 2025 EPA annual releases, a change of -3 points.

Compared against 236 monitored days in 2024 and 240 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: Wilmington, OH metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 41 over 243 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 202 Good days (83%), 38 Moderate (16%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 61 while the highest single-day reading hit 112 (USG). Metro residents averaged roughly 24.9 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 -5.4 points and the median AQI moved +2 points, which classifies the multi-year trajectory as worsening. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Adrian, MI (69.3% good, AQI 41); Albany-Schenectady-Troy, NY (67.7% good, AQI 41); Ann Arbor, MI (69.3% good, AQI 41).

Air Quality Summary

Median AQI

41

Good

Good Days

83.1%

202 of 243 days

Max AQI

112

USG

Health Grade

Good

90th pct: 61

AQI Day Breakdown (2025)

Distribution of 243 monitored days across EPA AQI categories.

Good

202

83%

Moderate

38

16%

USG

3

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Wilmington, OH metro area's air quality is rated Good based on 83.1% 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 Wilmington, OH metro compare?

How Wilmington, OH compares

Good-day share better than typical
Wilmington, OH 83.1%
Adrian, MI 69.3%
Typical US metro 70.6%
Median AQI about typical
Wilmington, OH 41
Adrian, MI 41
Typical US metro 41
Unhealthy days / yr better than typical
Wilmington, OH 0
Adrian, MI 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Wilmington, OH metro. Highest Good-day share: 2020 (89.5%, 205 of 229 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 205 24 0 39
2021 209 31 0 39
2022 216 28 0 40
2023 199 39 0 44
2024 176 60 0 44
2025 202 38 0 41

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Wilmington, OH (41).

Adrian, MI

Median AQI 41 · 69.3% Good-day share

41

Albany-Schenectady-Troy, NY

Median AQI 41 · 67.7% Good-day share

41

Ann Arbor, MI

Median AQI 41 · 69.3% Good-day share

41

Bowling Green, KY

Median AQI 41 · 75.6% Good-day share

41

Brunswick, GA

Median AQI 41 · 74.3% Good-day share

41

Decatur, AL

Median AQI 41 · 78.4% Good-day share

41

Metros with similar unhealthy-day exposure

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

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Alexandria, LA

0 unhealthy-or-worse days · median AQI 37

37

More Air Quality Data

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

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Wilmington, OH metro area? ▼
The Wilmington, OH metro area has a median Air Quality Index (AQI) of 41, rated "Good." 83.1% of monitored days (202 out of 243) had good air quality in 2025.
How many unhealthy air days does Wilmington, OH have? ▼
In 2025, the Wilmington, OH metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 112.
Is air quality in Wilmington, OH getting better or worse? ▼
Air quality in the Wilmington, OH metro is worsening 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 89.5% (205 of 229 days). Lowest qualifying Good-day share: 2024 at 74.6% (176 of 236 days).
What does AQI 41 mean for health? ▼
An AQI of 41 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 Wilmington, OH? ▼
The 90th percentile AQI for the Wilmington, OH metro area is 61, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 112 (USG).
How does Wilmington, OH compare to other metro areas? ▼
The Wilmington, OH metro has 83.1% good air days. Similar metros: Adrian, MI (69.3% good), Albany-Schenectady-Troy, NY (67.7% good), Ann Arbor, MI (69.3% 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.

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

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.