Wilmington Median AQI 2025: Historical Air Quality Data
Explore 2025 air quality data for Wilmington, including the median AQI, seasonal patterns, pollution trends, and how air quality changed over the year.
Current Air Quality
Air quality is satisfactory, and air pollution poses little or no risk.
Wilmington Air Quality in 2025
Historical air quality data for Wilmington in 2025 shows how pollution levels have changed over time. Understanding yearly trends helps identify seasonal patterns, the impact of local policies, and long-term air quality improvements or concerns in your area. Check current conditions below for today's AQI reading.
View Current Wilmington Air Quality →Wilmington 2025 Air Quality Snapshot
Across 2025, Wilmington's median AQI was around 42 (Good), based on current readings and seasonal patterns for the Philadelphia-Camden-Wilmington reporting area. That means a typical day fell near AQI 42, with the dominant pollutant being ground-level ozone (O3), which is common for the Mid-Atlantic region.
How Wilmington Air Quality Changed by Season in 2025
Spring (Mar–May): Usually Wilmington's cleanest stretch, with AQI near 24. Mild temperatures and better atmospheric mixing keep both ozone and particulates low.
Summer (Jun–Aug): AQI climbs toward 66 as heat and sunlight drive ozone formation to its yearly peak. Afternoons are the worst time to be outside.
Fall (Sep–Nov): Air quality generally improves as temperatures drop, though early fall can still carry wildfire smoke in the Mid-Atlantic region.
Winter (Dec–Feb): AQI near 44. Cold-air temperature inversions can trap PM2.5 from heating and vehicles close to the ground, especially on still mornings.
Is It Safe to Exercise Outside in Wilmington?
With Wilmington's AQI at 38 (Good), outdoor exercise is generally safe for most people. Conditions are good for running, cycling, and outdoor sports at any time of day.
See our running & AQI guide and cycling & AQI guide for activity-specific thresholds.
What's Causing Wilmington's Air Pollution?
In Wilmington, the leading pollutant is ground-level ozone (O3). As part of the Mid-Atlantic region, the main drivers of air pollution here are:
- •Heavy commuter traffic along the I-95 corridor
- •Regional ozone and particulate transport from upwind states
- •Industrial activity and power generation
- •Urban heat-island effects that amplify summer ozone
Dig deeper: Wilmington PM2.5 levels · Wilmington ozone levels
Air Purifier & Monitor Buying Guides
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PM2.5 Levels
Fine particulate matter data →
Ozone Levels
Ground-level ozone data →
Seasonal Guides
Air quality by season →
Health Effects
Learn about air pollution impacts →
Frequently Asked Questions About Wilmington Air Quality
What is the current air quality in Wilmington?
The current Air Quality Index (AQI) in Wilmington, DE is 38, which is considered good.
Is it safe to exercise outdoors in Wilmington?
Yes, with an AQI of 38, outdoor exercise is safe for everyone in Wilmington.
When is the best time of year to visit Wilmington for good air quality?
Spring and early fall typically offer the best air quality in Wilmington. Summer months may have elevated ozone levels, while winter can see higher PM2.5 from temperature inversions.
What causes air pollution in Wilmington?
Air pollution in Wilmington can come from vehicle emissions, industrial activity, construction, wildfires, and weather patterns. Local geography and seasonal factors also play a significant role.
Explore More Air Quality Data
Reduce Indoor Ozone in Wilmington
Today's main pollutant in Wilmington is ground-level ozone (AQI 38). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Compare activated-carbon purifiers (for gases & ozone):
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