The week as a whole has been a roller coaster ride; we've had onshore flows with highs barely reaching 80 in the beginning of the week while the middle of the week we reached 90, but then we ended the work week on a cooler note with another onshore flow. After a seasonably cool low of 61 at Philadelphia International Airport we reached a high of 81 in the afternoon just shortly after 2pm. There was an easterly wind through the afternoon with a mixture of sunshine and clouds.
Overnight there will be a few higher clouds around so lows will be in the lower 60s, but in the suburbs they will be in the middle and upper 50s; Saturday will feature sunshine giving way to clouds in the afternoon ahead of a warm front that will be pushing northward overnight into Sunday morning. Highs will be in the lower 80s with a southeast to southerly wind. Water temperatures will be in the lower to middle 70s, but there's still a small rip current risk around so be careful if you dip into the water(not every lifeguard post is manned as a lot of them are now back at school).
Once that warm front pushes through we will have higher dewpoints and that "muggy" feeling will be back so in all honesty it will feel more like the Fourth of July with highs near 90; another issue arises since we have a hot and humid air mass on top of us there will be isolated showers and thunderstorms in the afternoon. It will be deja vu come Labor Day after a muggy low of 70 we'll once again be near 90 with an isolated shower or thunderstorm in the afternoon.
Come Tuesday a cold front from the west will progress eastward; we'll be in the lower 90s ahead of it with that continued muggy and humid southerly flow, but there will be a better shot for showers and thunderstorms in the late afternoon leading into the evening. Although behind the front on Wednesday and Thursday we'll be in the middle 80s at least the humidity drops off a bit with a northerly flow.
Have a safe Labor Day weekend and I'll be around all weekend as well so keep checking my 7-day forecast(as well as viewing the satellite and radar maps 24/7) at www.scottderekwx.com/forecast.html.