Pennsylvania air quality

Aldan, Pennsylvania Air Quality

Delaware County39.922, -75.288

The nearest monitor to Aldan, at RIT, 5 miles away, measured an index of 22 at Fri, 7:00 AM EDT, which is Good for fine particles (PM2.5). Pennsylvania Dept. of Environmental Protection forecasts Good for Philadelphia today and Good tomorrow.

Measured now
22 · Good
Today
35 · Good
Tomorrow
32 · Good
Pollutant
PM2.5

Fine particles on the map

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

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Aldan, Pennsylvania 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 Aldan right now. All Pennsylvania warnings.

Now

Good

Nearest monitor
RIT, 5 miles away (site 421010055)
Index measured
22 · Good
Measured at
Fri, 7:00 AM EDT
Fine particles
4.3 µg/m³
Reporting area
Philadelphia, PA, 8 miles away
Reported by
Pennsylvania Dept. of Environmental Protection
Area index
29 · Good

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

Today and tomorrow

Pennsylvania Dept. of Environmental Protection's own forecast for Philadelphia, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGood35Ozone
TomorrowGood32PM2.5
Sunday, September 27GoodPM2.5

The forecaster’s discussion

Written by Pennsylvania Dept. of Environmental Protection for Philadelphia and filed with AirNow.

Current Conditions at 3 p.m. EDT this Thursday afternoon: Skies are partly sunny with a cool northeast wind as temperatures struggle in the middle 60s. Clean air continues to be transported in, so fine particle (PM2.5) and ozone levels are well down inside the good range. A coastal low pressure system will back into the east coast over the next few days and cause unsettled weather over the weekend. Here are the forecast details: *** Friday’s forecast: Sunshine and some mid and high level clouds Friday. Highs will reach around 70 degrees with a stiff northeast breeze keeping PM2.5 and ozone low in concentration. *** Extended forecast: An unsettled weekend is likely with periods of windy and rainy conditions as low pressure comes closer to the east coast. Highs Saturday and Sunday will be held to the middle 60s with low ozone and PM2.5 values. Clouds might break for a little sun Monday, but still on the cool side with good air quality.---McAuliffe

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 41, Good, around Sun, 10:00 PM EDT, from the run issued Fri, 2:00 AM EDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Fri, 9:00 AM EDT23Good3.9
Fri, 10:00 AM EDT22Good3.717.2
Fri, 11:00 AM EDT22Good418.1
Fri, 12:00 PM EDT23Good4.819.2
Fri, 1:00 PM EDT25Good5.420.7
Fri, 2:00 PM EDT27Good5.522.7
Fri, 3:00 PM EDT28Good5.625.3
Fri, 4:00 PM EDT27Good4.527.8
Fri, 5:00 PM EDT27Good3.929.5
Fri, 6:00 PM EDT28Good3.730.3
Fri, 7:00 PM EDT28Good3.130.2
Fri, 8:00 PM EDT27Good3.129.8
Fri, 9:00 PM EDT26Good3.628.7
Fri, 10:00 PM EDT24Good4.526.9
Fri, 11:00 PM EDT22Good4.224.7
Sat, 12:00 AM EDT23Good4.522.5
Sat, 1:00 AM EDT24Good4.520.9
Sat, 2:00 AM EDT22Good3.520.1
Sat, 3:00 AM EDT19Good2.820
Sat, 4:00 AM EDT19Good1.920.5
Sat, 5:00 AM EDT19Good1.921.8
Sat, 6:00 AM EDT21Good1.823.4
Sat, 7:00 AM EDT22Good1.824.9
Sat, 8:00 AM EDT24Good1.726.5
Sat, 9:00 AM EDT26Good1.928
Sat, 10:00 AM EDT27Good2.129.3
Sat, 11:00 AM EDT28Good2.130.3
Sat, 12:00 PM EDT28Good2.530.6
Sat, 1:00 PM EDT28Good2.930.3
Sat, 2:00 PM EDT27Good3.629.5
Sat, 3:00 PM EDT26Good528.6
Sat, 4:00 PM EDT26Good5.227.5
Sat, 5:00 PM EDT26Good4.726.8
Sat, 6:00 PM EDT24Good426.1
Sat, 7:00 PM EDT24Good4.425.3
Sat, 8:00 PM EDT23Good4.124.7
Sat, 9:00 PM EDT22Good3.424.7
Sat, 10:00 PM EDT23Good4.525.1
Sat, 11:00 PM EDT23Good3.825.6
Sun, 12:00 AM EDT24Good3.826.4
Sun, 1:00 AM EDT24Good4.126.8
Sun, 2:00 AM EDT25Good3.527.2
Sun, 3:00 AM EDT25Good2.627.4
Sun, 4:00 AM EDT25Good2.527.2
Sun, 5:00 AM EDT24Good2.826.8
Sun, 6:00 AM EDT24Good2.726.1
Sun, 7:00 AM EDT23Good2.725.5
Sun, 8:00 AM EDT23Good2.525
Sun, 9:00 AM EDT22Good2.724.7
Sun, 10:00 AM EDT22Good2.924.2
Sun, 11:00 AM EDT22Good3.124.2
Sun, 12:00 PM EDT22Good3.424.4
Sun, 1:00 PM EDT22Good3.624.3
Sun, 2:00 PM EDT23Good524.4
Sun, 3:00 PM EDT30Good6.724.4
Sun, 4:00 PM EDT33Good6.623.8
Sun, 5:00 PM EDT34Good6.422.9
Sun, 6:00 PM EDT34Good6.121.8
Sun, 7:00 PM EDT36Good6.720.7
Sun, 8:00 PM EDT36Good6.819.8
Sun, 9:00 PM EDT39Good7.619.3
Sun, 10:00 PM EDT41Good7.919.2
Sun, 11:00 PM EDT37Good5.919.7
Mon, 12:00 AM EDT32Good4.920.7
Mon, 1:00 AM EDT29Good4.622
Mon, 2:00 AM EDT27Good4.523.2

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 Aldan in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 0.1 µg/m³ around Fri, 10:00 PM EDT.

Smoke on the radar over Aldan

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 AldanWarnings in Delaware CountyLive radar over AldanPennsylvania 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.