With skies generally clear or at least with passing high clouds, temperatures will have a tendency to drop off a fair bit overnight. Expect lows outside of the city to drop into the mid 20's in the coldest spots while the city and areas along the river, plus the Shore, get to around freezing by daybreak. Chilled but nothing terrible.
Tomorrow will feature temperatures a couple of degrees milder than today with a mix of clouds and sunshine -- high temperatures will likely top out in the lower and middle 50's through the region, warmest to the south in Delaware. Winds tonight will be light, a bit breezier tomorrow but nothing that you can't tolerate.