Philly Area Heat Wave: Triple Digit Temps Thursday, Friday

SOUTHEASTERN PA — The Delaware Valley is not finished with the severe heat just yet. High temperatures approaching 100 degrees or higher are expected to hit the greater Philadelphia area over the next two days.

The National Weather Service has issued a heat advisory for all five suburban Philadelphia counties, in effect from noon on Thursday through 8 p.m. on Friday.

Forecasters are predicting maximum heat index values around 100 on Thursday and anywhere from 100 to 104 on Friday, meaning heat exhaustion or heat stroke are possible with prolonged exposure to the elements

On Thursday, the Pennsylvania Department of Environmental Protection also declared an Air Quality Action Day for the Region.

Heat & humidity continue to build into the region. Highs in the low 90s combined with dew points in the 70s will result in max Heat Index values around 100 today, & from 100-104 on Friday. A Heat Advisory is in effect for most of the region. Stay cool & hydrated!! pic.twitter.com/UpA8VdBhsF
— NWS Mount Holly (@NWS_MountHolly) August 26, 2021

"Hot temperatures and high humidity may cause heat illnesses to occur," the National Weather Service said in the alert.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances," the agency said in the advisory.

"Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9-1-1."

In addition to the stifling heat, a slight chance of thunderstorms is possible on Friday night, according to the National Weather Service. An increased chance of scattered thunderstorms is expected to last into the weekend, though temperatures are expected to drop down to the mid-70s on Saturday and Sunday.

Here’s the latest forecast:

Thursday: A slight chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Calm wind becoming southwest around 5 mph in the afternoon. Chance of precipitation is 20%.

Thursday night: Partly cloudy, with a low around 74. South wind around 5 mph becoming calm after midnight.

Friday: A slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 93. Heat index values as high as 102. Calm wind becoming southwest around 5 mph in the afternoon. Chance of precipitation is 20%.

Friday night: A chance of showers and thunderstorms. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 75. Southeast wind around 5 mph becoming calm. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2pm. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 87. East wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Saturday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 72. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Sunday: A chance of showers and thunderstorms after 2pm. Patchy fog before 8am. Otherwise, partly sunny, with a high near 88. Chance of precipitation is 30%.

Sunday night: A chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 73. Chance of precipitation is 30%.