Wilmington Air Quality in 2019

In 2019, Wilmington's air quality (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD area) had a median daily AQI of 56 (Moderate) across 365 monitored days. 16 days (4.4%) reached Unhealthy for Sensitive Groups or worse, 113 were Good, and the year's peak AQI was 150 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 258 of those days. The cleanest month of 2019 was October (median AQI 42, 0 days above 100) and the worst was July (median 67, 6 days above 100, peak 150).

56
Median AQI
Moderate
16
Days above AQI 100
4.4% of 365 days
84
90th percentile AQI
worst 1 day in 10
150
Peak AQI
Unhealthy for Sensitive Groups
PM2.5
Main pollutant
258 of 365 days
113
Good days
31.0% of days
  • Good: 31.0%
  • Moderate: 64.7%
  • Unhealthy for Sensitive Groups: 4.4%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How was Wilmington's air quality in 2019?

Moderate on a typical day: median AQI 56, with 16 days above AQI 100 out of 365 monitored — the 6th cleanest of 7 years on record for the area.

  • Peak AQI in 2019: 150 (Unhealthy for Sensitive Groups).
  • Fine particulate matter (PM2.5) was the main pollutant on 258 days.
  • Cleanest month: October; worst: July.

Frequently asked questions

What was the average AQI in Wilmington in 2019?

EPA's Air Quality System puts Wilmington's (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD) median daily AQI for 2019 at 56, which is Moderate. 16 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 150.

Which month had the worst air quality in Wilmington in 2019?

The cleanest month of 2019 was October (median AQI 42, 0 days above 100) and the worst was July (median 67, 6 days above 100, peak 150).

Was 2019 a good or bad year for Wilmington's air?

Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 6th cleanest by days above AQI 100. 2019's median of 56 is in line with the area's typical annual median of 56.

Wilmington month by month in 2019

Wilmington air quality month by month, 2019 (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January31642131PM2.5
February28551102PM2.5
March3156081PM2.5
April3048074PM2.5
May3153087PM2.5
June30583136PM2.5
Julyworst31676150O3
August31591105PM2.5
September30531105PM2.5
Octobercleanest31420100PM2.5
November3059085PM2.5
December31592133PM2.5

How 2019 compares

Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 6th cleanest by days above AQI 100.

2019's median of 56 is in line with the area's typical annual median of 56.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Wilmington

The latest EPA AirNow observation puts Wilmington's AQI at 52 (PM2.5). The figures above are multi-year annual statistics, not today's reading.

View current Wilmington air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.