The highest AQ index in Pennsylvania (as of 13:00 EST) is currently the Susquehanna Valley area. Particle Pollution (PM2.5) is measuring at 111 (Unhealthy for Sensitive Groups). This means members of sensitive groups may experience health effects. The general public is less likely to be affected.
Over the next few days, the highest Particle Pollution (PM2.5) will be in the Philadelphia area. It is forecasted to be Moderate, meaning air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
Current Conditions as of 3 PM on Monday: clouds at multiple levels in the atmosphere associated with an upstream system over the Midwest and a departing system over New England are making for a cool and cloudy day with moderate fine particulate (PM2.5) concentrations. Moderate concentrations are expected to continue overnight with light winds and a temperature inversion setting up with very warm air a few thousand feet overhead trapping cool, moist air at the surface. ***Tuesday’s Forecast: As the temperature inversion continues Tuesday morning through most of the day, along with very light winds under 5mph, and cloudy skies, will create conditions for a 24-hour period of high-moderate concentrations of PM2.5 being trapped near the surface. NOTE: several hours of unhealthy (orange AQI level) concentrations are possible in the morning and in the evening with the lowest concentrations in the afternoon (yellow AQI level) when the winds turn easterly and surface temperatures warm to the low-40’s. ***Extended Outlook: Wednesday will feature more moderate PM2.5 concentrations in the morning before a cool front moves through the region with increased sunshine and a westerly breeze helping to clean out the air mass into the good range, but the 24-hour average will still be in the low-moderate range. High pressure will briefly work its way into the Region on Thursday providing for tranquil and slightly warmer conditions than as of late with mostly good air quality, with some hours of moderate PM2.5 in the morning and evening. Another system moving in from the Plains on Friday looks to bring increased chances for precipitation through the weekend and continued above average temperatures, but also the risk for a return of moderate PM2.5 conditions. ---VanLenten
| Range | 0 - 50 | 51 - 100 | 101 - 150 | 151 - 200 | 201 - 300 | 301 - 500 |
| Color | ||||||
| Category | Good | Moderate | Unhealthy for Sensitive Groups | Unhealthy | Very Unhealthy | Hazardous |
Last Updated 7 minutes ago
Below is a list of counties in Pennsylvania. Click on any county below and you'll get a list of cities where we provide AQ index forecasts.