Excessive heat warning for Philly area

Betty Lu Guapo, 4, cools off in the heat at the Los Angeles Fountain Thursday June 27, 2013 in Los Angeles. California prepared Thursday for a scorching weekend that could see temperatures hit 120 in the deserts as a massive heat wave rolled through the West, authorities said. (AP Photo/Nick Ut)

The National Weather Service has issued an excessive heat warning for the Philadelphia area for the weekend.

The weather service says the watch will be in effect from 11 a.m. Saturday through 8 p.m. Sunday. The watch covers the Interstate 95 corridor from Wilmington to Trenton.

Temperatures ranging from 92 to 96 degrees are expected, with heat index values between 100 and 102 degrees. The hottest temperatures will be between noon and 8 p.m. each day, the weather service says.

Overnight, temperatures are likely to drop only to the mid-70s.

An excessive heat warning means that a prolonged period of hot temperatures will occur. The combination of high temperatures and high humidity could lead to heat-related illnesses.

With the temperature already having reached 90 degrees today, the weekend should produce the third heat wave of the summer.

The rest of today and Saturday are expected to be mostly sunny. There's a chance of showers and thunderstorms on Sunday, especially after 2 p.m.

Contact Emily Babay at 215-854-2153 or ebabay@philly.com. Follow @emilybabay on Twitter.

Contact the Breaking News Desk at 215-854-2443; BreakingNewsDesk@philly.com. Follow @phillynews on Twitter.