Weather Authority: Late-summer heat wave could bake Delaware Valley in days ahead

Don't pull out the Fall decorations and flannel shirts just yet, summer is still here and it will make its presence felt this week with temperatures in the 90s that could culminate in yet another heat wave. 

Warm air from the south will move into the Delaware Valley on Monday and combine with bright sunshine to help temperatures become uncomfortably hot for the first half of the week. 

Forecasters expect thermometers to strike 90 degrees on both Monday and Wednesday. Similar conditions will be felt on Tuesday, but the potential heat wave will hinge upon temperatures reaching the 90 degree mark. 

The average high temperatures for this time of year in Philadelphia and its suburbs is 82 degrees. The National Weather Service said the hottest Sept. 13 ever recorded was nearly 70 years ago when the city reached 95 degrees. 

"The good news about Monday is that although it will be warmer than normal, anywhere from around 5 to 10 degrees, our high temperature records will be safe," the weather service said in a tweet. 

There is a possibility, north and west of the city, overnight Monday into Tuesday for pop-up thunderstorms. 

Temperatures will return to seasonable levels on Thursday with showers and thunderstorms that will linger into Friday. There's also a possibility for those thunderstorms to last into Saturday, but the forecast isn't firm on that yet. 

A beautiful weekend will follow the unsettled weather pattern, including a gorgeous Sunday for the Eagles home opener.


MONDAY: Sunny, hot. High: 90, Low: 72

TUESDAY: Very warm. High: 90, Low: 72

WEDNESDAY: Heat continues. High: 90, Low: 71

THURSDAY: Showers, storms. High: 81, Low: 71



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