Two nights in a row of good weather in early April in Philly?
That was my other thought. That evening might be 55 or it might be 35.
Looking at Philly's weather from the past five years, I'm gonna use the temps between 6pm and midnight. I'm also posting the first two weeks of the month to provide a better range of weather during that time of year.
2022
First weekend: 55/45 (Saturday) and 52/45 (Sunday)
Second weekend: 54/50 and 52/45
2021
First weekend: 52/46 and 66/54
Second weekend: 68/59 and 64/48*
2020
First weekend: 55/48 and 64/55*
Second weekend: 55/39 and 66/57*
2019
First weekend: 66/46 and 64/54*
Second weekend: 72/59 and 72/70
2018
First weekend: 45/39 and 46/36
Second weekend: 79/48 and 41/39*
* - rained after 6pm that evening