This first full week of Spring will have temperatures move from near to below average highs on Tuesday into the warm range by Friday and Saturday.
The statistical model based on the GFS ensemble, (EKDMOS) shows the possible range of high temperatures this coming week:
So it’s possible that we could see high temperatures in the mid to upper 70s. (Notice that the “spread” between possible high temperatures is quite large by 3/30.)
The average low is 38 and average high is 57 for Philadelphia this week.