Frost advisories and freeze warnings are out for just about the entire region tonight -- save the city of Philadelphia and the Shore. Yeah, it's going to be cold in the region tonight as cold air surges in over the next few hours and sets us up for the coldest night of October so far.
Lows tonight could get down into the upper 20's in Allentown or Reading if some of the colder modeling out there (GFS) is correct. In our outer burbs, we're projecting 32-34 for many locations but it wouldn't surprise me if a few spots are colder than that in the morning.
The city is projected to get into the mid and upper 30's -- coldest since April -- but safely above the frost point in Center City, South Philly, and in the more populated parts of the city. However, it would not surprise me if Fairmount Park and Chestnut Hill get some frost in patchy spots overnight if the Airport drops below 40.
As far as records are concerned...courtesy of the National Weather Service...
PHILADELPHIA, PA....32 SET BACK IN 1988. ALLENTOWN, PA.......30 SET BACK IN 2006. READING, PA.........29 SET BACK IN 1906. MOUNT POCONO, PA....17 SET BACK IN 1906. TRENTON, NJ.........27 SET BACK IN 1987. ATLANTIC CITY, NJ...29 SET BACK IN 1988. WILMINGTON, DE......32 SET BACK IN 1934/1917. GEORGETOWN, DE......29 SET BACK IN 1957.
The most likely locations to see a record low tonight would be Allentown and Reading. If everything breaks right, AC and Trenton could come close. The records range all over the place, with 1988 and 1906 the "most" common of the years listed. Regardless, a cold night by October standards is ahead.