Philadelphia August 6, 2018 11:52 pm NBC10 First Alert Weather: How Long Will the Heat Wave Last? How long will the heat wave last? NBC10 First Alert Weather chief meteorologist Tammie Souza has the forecast. US & World Videos 3:10 Summer-like temps for most the area, except by the shore 3:33 Summer-like temperatures continue 2:39 Gloomy Sunday morning expected to clear for sunny afternoon 2:50 One more cool day, then warmer weather ahead 3:15 Cold night, then a big warmup this weekend