The highest AQ index in Pennsylvania (as of 17:00 EDT) is currently the Lehigh Valley area. Ozone (OZONE) is measuring at 46 (Good). This means air quality is satisfactory, and air pollution poses little or no risk.
Over the next few days, the highest Particle Pollution (PM2.5) will be in the Liberty-Clairton Area 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 at 3 p.m. Friday afternoon: Low-moderate fine particulate (PM2.5) concentrations started out the day but improving as high pressure builds in from the Midwest. The northerly, breezy winds will keep the air mass well mixed and PM2.5 concentrations in the good range overnight. ***Saturday’s Forecast: Another cooler-than-average will start the weekend with a mix of sun and clouds with a continued cool, northwesterly breeze. Although the temperatures are not ideal, the resulting air quality will be and continue to stay in the good range. ***Sunday’s Forecast: A weak temperature inversion, and light southwest winds will occur by the early morning hours which should cause the PM2.5 concentrations to rise into the mid-moderate range for several hours until the southwest winds help the surface temperature warm enough by mid-morning to erode the inversion. With the inversion removed, and temperatures rising into the 50’s, adequate vertical and horizontal mixing should lower the morning’s moderate PM2.5 concentrations into the good range the rest of the day. ***Monday’s Forecast: The trend back to above average temperatures will continue as March ends and April begins with a chance of afternoon rain as a frontal boundary hangs near the region. The rainy conditions will promote moderate PM2.5, however, the breezy southwest winds should cap PM2.5 in the low-moderate range. ***Extended Outlook: More of the same weather as Monday: warmer with temperatures in the low- to upper-70’s, but with daily chances for precipitation and continued low-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 4 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.