Frost advisory active for 4 N.J. counties Friday

At 1:56 a.m. on Thursday, the National Weather Service issued a frost advisory valid for Friday between 2 a.m. and 9 a.m. for Morris, Hunterdon, Somerset and Mercer counties.

The weather service says to expect, “Temperatures in the low to mid 30s will result in frost formation.”

“Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered,” says the weather service. “Take steps now to protect tender plants from the cold.”