4 Days Of 90+ Temps In PA Kick Off Wednesday: See Timeline

PENNSYLVANIA - Wednesday marks the start of a scorching four days of heat in the Keystone State, with most of the state already under a heat-related advisory or air quality alert as of Wednesday morning.

Wednesday’s temperatures at 90 degrees will climb to a high on Thursday and Friday at around 96 degrees, the National Weather Service said. Believe it or not, Friday will feel even hotter with heat indices - what the temperature feels like to the human body - at over 105 degrees in areas like Philadelphia and Wilmington and 106 in Reading.

Heat indices of 92 degrees are expected in Mount Pocono and 103 degrees in Allentown. Thursday brings another chance of severe storms in the evening, the weather service said.

“Oppressively hot and humid conditions will build through Fri. Heat Advisories have been issued for portions of the region, the National Weather Service’s Mount Holly station said in a statement. “Very warm and muggy conditions at night will not provide much relief from the heat.”

🔥🥵 Oppressively hot and humid conditions will build through Fri. Heat Advisories have been issued for portions of the region. Very warm and muggy conditions at night will not provide much relief from the heat. Severe storms are possible again on Thurs. #PAwx #NJwx #DEwx #MDwx pic.twitter.com/P88OsayQye
— NWS Mount Holly (@NWS_MountHolly) July 26, 2023

A several day heat wave begins today and peaks on Friday. Daytime high temperatures will fall back to slightly below normal on Sunday. #CTPWX #PAWX pic.twitter.com/OwMxPAQqgC
— NWS State College (@NWSStateCollege) July 26, 2023

Over a dozen Pennsylvania counties are under a heat advisory from 11 a.m.. Thursday through 6 p.m. Friday. The affected counties are:

• Delaware
• Philadelphia
• Chester
• Montgomery
• Bucks
• Berks
• Lehigh
• Northampton
• Franklin
• Perry
• Dauphin
• Lebanon
• Cumberland
• Adams
• York
• Lancaster

“Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities,” the National Weather Service said, adding that car interiors can reach deadly temperatures in a matter of minutes during extreme heat.

The blazing temperatures between Thursday and Saturday is forecast to be a moderate heat wave, Accuweather said.

Air quality will decrease during the heatwave, with the Delaware Valley Regional Planning Commission issuing a code orange air quality alert for parts of the state on Wednesday. The affected counties are Delaware, Philadelphia, Chester, Montgomery and Bucks.

“Air pollution concentrations within the region may become unhealthy for sensitive groups,” the National Weather Service said. “Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors.”

Hot and humid conditions will persist through Saturday; Friday is expected to see sunny skies before another possible round of thunderstorms on Saturday afternoon, the weather service said.

Forecasters say that fans of cooler temperatures may get a break from the scorching heat soon as a cold front over the weekend is expected to bring cooler weather by Sunday with temperatures dropping to 85 degrees by Sunday afternoon and around 62 degrees by Sunday night.

Here’s the latest forecast around Pennsylvania, per the National Weather Service:

Wednesday: Sunny, with a high near 87. Light and variable wind becoming south 5 to 10 mph in the afternoon.

Wednesday: Mostly clear, with a low around 74. South wind around 10 mph.

Thursday: Sunny, with a high near 93. Heat index values as high as 102. Southwest wind around 15 mph.

Thursday Night: A chance of showers and thunderstorms, mainly between 8 p.m. and 2 a.m. Partly cloudy, with a low around 76. South wind 10 to 15 mph. Chance of precipitation is 30 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Friday: Sunny, with a high near 94. Southwest wind around 10 mph.

Friday Night: Partly cloudy, with a low around 78.