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Pennsylvania Air Quality

Pittsburgh is the worst air in Pennsylvania right now at an index of 52, which is Moderate, from fine particles (PM2.5). AirNow carries 13 reporting areas in the state. No air quality alert is in force.

Reporting areas: 13
Worst index now: 52
Alerts in force: 0
Towns under smoke: Unavailable

Radar

Reflectivity now over Pennsylvania. Open it to see the particulate forecast on the map.

Open the live radar with the particulate forecast

Radar mosaic and map layers from NOAA MRMS and 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 in Pennsylvania right now. All Pennsylvania warnings.

By city, now and the days ahead13

Every AirNow reporting area in Pennsylvania: what its monitors measured this hour, and what the state or local agency that forecasts for it expects today and tomorrow. Each area links to the nearest town’s page.

Reporting area	Now	Category now	Today	Tomorrow	Pollutant
Pittsburgh	52	Moderate	Good	Good	PM2.5
Philadelphia	47	Good	Good	Good	PM2.5
Mon Valley Area	41	Good	Good	Good	PM2.5
Altoona	40	Good	Good	Good	PM2.5
Johnstown	34	Good	Good	Good	PM2.5
Mercer County	32	Good	Good	Good	PM2.5
State College	29	Good	Good	Good	PM2.5
Susquehanna Valley	29	Good	Good	Good	PM2.5
Indiana County	28	Good	Good	Good	PM2.5
Erie	23	Good	Good	Good	PM2.5
Lehigh Valley	22	Good	Good	Good	Ozone
Scranton and Wilkes-Barre	20	Good	Good	Good	Ozone
Williamsport	19	Good	Good	Good	Ozone

The forecaster’s discussion

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

Current Conditions at 4 PM EDT this Friday afternoon: Clouds are breaking up some across the area. A northerly flow of clean air is improving PM2.5 and ozone to the good range. Good air quality is expected the next few days, but weather systems coming in from the west will lead to unsettled conditions Sunday into early next week. Here are the forecast details: *** Saturday’s forecast: Clouds and a little sunshine Saturday with a light southeast wind and highs in the middle and upper 70s. Ozone and PM2.5 concentrations will average in the high good range. Showers and a thunderstorm will move in Saturday night. *** Sunday’s forecast: Mostly cloudy Sunday with additional showers and a thunderstorm. Air quality will remain in the high good range as highs are limited to the lower 70s. *** Monday’s forecast: Mostly cloudy and not as warm Monday with a couple of showers as highs only reach the upper 60s. *** Extended forecast: An unsettled weather pattern remains as we move into the middle of the week. Fall will officially arrive at 8:04 pm EDT Tuesday evening. Plenty of cloudiness Tuesday and Wednesday with the chance for showers and a thunderstorm both days. Cool with high temperatures being limited to the middle 60s. Air quality mainly in the good range.---McAuliffe

Smoke

NOAA’s Hazard Mapping System smoke analysis could not be read just now.

Smoke on the radar over Pennsylvania

What this means

The index runs from 0 to 500. Good is 0 to 50, Moderate to 100, Unhealthy for Sensitive Groups to 150, Unhealthy to 200, Very Unhealthy to 300, and Hazardous above that. The figure reported for a place is the highest index among the pollutants measured there, and the pollutant that produced it is named beside it.

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.

Towns

Air quality for any town in Pennsylvania: what is measured nearby, the category forecast for today and tomorrow, and NOAA’s model hour by hour. Largest first.

922 smaller towns

Smaller places have pages too; search for one on the air quality landing page.

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.