**Tuesday’s forecast: An Air Quality Action Day is in effect for Tuesday for ozone! Ozone development is expected to be robust with the lack of cloudiness and precipitation under a mostly sunny sky. Code ORANGE concentrations will thus occur for parts of the area Tuesday afternoon. Still low relative humidity means PM2.5 will remain at upper good levels.


*** Extended forecast: More humid Wednesday with periods of clouds and sunshine. A thunderstorm is possible late in the day or in the evening. Ozone levels will still remain elevated, but should only reach the middle moderate range. Higher atmospheric humidity and light winds will bring fine particulate concentrations to the moderate range. A shower may linger Thursday morning as a cold front comes through, otherwise the balance of Thursday and Friday should be dry with sunshine returning. Particle and ozone levels will range from the upper good to the lower moderate range.---McAuliffe


Tuesday is an Air Quality Action Day. Please protect your health by limiting strenuous outdoor activities.

Help prevent air pollution by:

  • Taking transit

  • Refueling your vehicle at night

  • Conserving energy in your home


To follow air quality in PHL between forecasts:


For more information, contact the Air Quality Partnership at 215-238-2860.