Delaware air quality

Wilmington, Delaware Air Quality

New Castle County39.746, -75.547

The nearest monitor to Wilmington, at MLK, under a mile away, measured an index of 23 at Tue, 4:00 PM EDT, which is Good for fine particles (PM2.5). Delaware Dept. of Natural Resources and Environment forecasts Good for Wilmington Area today and Good tomorrow.

Measured now
23 · Good
Today
32 · Good
Tomorrow
30 · Good
Pollutant
PM2.5

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Wilmington, Delaware. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Wilmington, Delaware Open the live map with the particulate forecast

Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force near Wilmington right now. All Delaware warnings.

Now

Good

Nearest monitor
MLK, under a mile away (site 100032004)
Index measured
23 · Good
Measured at
Tue, 4:00 PM EDT
Fine particles
4.2 µg/m³
Ozone
18 ppb
Reporting area
Wilmington Area, DE, under a mile away
Reported by
Delaware Dept. of Natural Resources and Environment
Area index
24 · Good

Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.

Today and tomorrow

Delaware Dept. of Natural Resources and Environment's own forecast for Wilmington Area, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGood32Ozone
TomorrowGood30Ozone
Thursday, September 24Good33Ozone
Friday, September 25Good37Ozone

The forecaster’s discussion

Written by Delaware Dept. of Natural Resources and Environment for Wilmington Area and filed with AirNow.

Wednesday, September 23 through Friday, September 25: As a surface low gradually strengthens offshore, and a surface high remains anchored to the north, gusty northeasterly winds will aid dispersion and transport clean air into the Mid-Atlantic each day. In addition, partly to mostly cloudy skies and cool temperatures will hinder ozone development. As a result, AQI levels are anticipated to be Good for ozone and PM2.5 on all three days.

Hour by hour

NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 53, Moderate, around Thu, 10:00 PM EDT, from the run issued Tue, 8:00 AM EDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Tue, 10:00 AM EDT24Good4.9
Tue, 11:00 AM EDT24Good4.2
Tue, 12:00 PM EDT23Good3.7
Tue, 1:00 PM EDT22Good3.7
Tue, 2:00 PM EDT21Good3.7
Tue, 3:00 PM EDT19Good3.2
Tue, 4:00 PM EDT16Good2.46.4
Tue, 5:00 PM EDT15Good2.55.1
Tue, 6:00 PM EDT13Good2.34.1
Tue, 7:00 PM EDT13Good2.33.3
Tue, 8:00 PM EDT14Good2.83
Tue, 9:00 PM EDT11Good1.53.7
Tue, 10:00 PM EDT7Good0.75.3
Tue, 11:00 PM EDT6Good0.47
Wed, 12:00 AM EDT7Good0.49
Wed, 1:00 AM EDT10Good0.111.3
Wed, 2:00 AM EDT12Good0.113.9
Wed, 3:00 AM EDT15Good0.216.1
Wed, 4:00 AM EDT16Good0.317.7
Wed, 5:00 AM EDT16Good0.818
Wed, 6:00 AM EDT16Good1.317.9
Wed, 7:00 AM EDT16Good117.2
Wed, 8:00 AM EDT15Good0.816.3
Wed, 9:00 AM EDT14Good1.815.2
Wed, 10:00 AM EDT12Good2.613.9
Wed, 11:00 AM EDT13Good2.813.4
Wed, 12:00 PM EDT13Good2.314
Wed, 1:00 PM EDT15Good1.116
Wed, 2:00 PM EDT16Good0.717.7
Wed, 3:00 PM EDT18Good1.219.8
Wed, 4:00 PM EDT19Good0.821.3
Wed, 5:00 PM EDT20Good0.922.7
Wed, 6:00 PM EDT22Good1.324.2
Wed, 7:00 PM EDT23Good1.325.3
Wed, 8:00 PM EDT23Good0.825.4
Wed, 9:00 PM EDT21Good2.923.9
Wed, 10:00 PM EDT20Good222
Wed, 11:00 PM EDT19Good220.5
Thu, 12:00 AM EDT18Good1.919.6
Thu, 1:00 AM EDT17Good1.618.7
Thu, 2:00 AM EDT16Good1.317.8
Thu, 3:00 AM EDT15Good0.616.5
Thu, 4:00 AM EDT14Good0.715.4
Thu, 5:00 AM EDT13Good0.914.9
Thu, 6:00 AM EDT13Good1.414.8
Thu, 7:00 AM EDT13Good1.114.7
Thu, 8:00 AM EDT13Good1.414.1
Thu, 9:00 AM EDT12Good2.113.4
Thu, 10:00 AM EDT12Good2.313.1
Thu, 11:00 AM EDT12Good1.813.3
Thu, 12:00 PM EDT13Good1.614.1
Thu, 1:00 PM EDT14Good1.815.9
Thu, 2:00 PM EDT17Good2.818.1
Thu, 3:00 PM EDT19Good3.121
Thu, 4:00 PM EDT22Good3.624.2
Thu, 5:00 PM EDT25Good4.827.6
Thu, 6:00 PM EDT28Good6.130.5
Thu, 7:00 PM EDT33Good6.832.6
Thu, 8:00 PM EDT39Good8.233.3
Thu, 9:00 PM EDT47Good1032.3
Thu, 10:00 PM EDT53Moderate11.830.5
Thu, 11:00 PM EDT52Moderate928.4
Fri, 12:00 AM EDT47Good7.326.5
Fri, 1:00 AM EDT40Good624.3
Fri, 2:00 AM EDT35Good5.422.3
Fri, 3:00 AM EDT29Good4.420.6
Fri, 4:00 AM EDT24Good3.519.5
Fri, 5:00 AM EDT19Good2.519.3
Fri, 6:00 AM EDT18Good2.819.4
Fri, 7:00 AM EDT18Good2.619.2
Fri, 8:00 AM EDT18Good3.618.4

Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.

Smoke

NOAA’s analysts have not drawn smoke over Wilmington in satellite imagery today.

NOAA’s model forecasts no measurable smoke near the ground here over the next two days.

Smoke on the radar over Wilmington

What this means

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Who is affected
Nobody is expected to be affected.
What to do
It is a good day to be outside.
Index range
0 to 50

Category descriptions are the Environmental Protection Agency’s own.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Nearby

The nearest towns with a page of their own, closest first.

Weather forecast for WilmingtonWarnings in New Castle CountyLive radar over WilmingtonDelaware air quality

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.