Philly is pretty typical mid-Atlantic weather. Summers are a bit hotter/muggier (especially in the city) than some might like and winters have more snow than some would like. Personally, I prefer the weather in New England on balance but it comes down to your tolerance for winter.

I'd actually have said Philly had better weather than DC though. It's enough further south that summers are starting to get more southeastern in temperature/humidity (which I personally hate) and, while winters are milder, snow storms still happen but they're infrequent enough that chaos ensues.