Excessive Heat Warning Issued for Delaware Valley

The National Weather Service issued an excessive heat warning through 8 p.m. Sunday for the Delaware Valley, including Philadelphia, Montgomery, Bucks, Chester and Delaware Counties. 

The heat index value is expected to reach around 100 degrees, according to the agency.

"An excessive heat warning means that a prolonged period of dangerously hot temperatures will occur. The combination of hot temperatures and high humidity will create a dangerous situation in which heat illnesses are likely," the NWS said in its warning.

The NWS is expecting temperatures to peak sometime between Saturday afternoon and early evening before dipping to between 75 and 80 degrees when night falls. Temperatures will spike again on Sunday afternoon, according to the agency.