SAN DIEGO COUNTY COASTAL AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY VALLEYS-With a cold atmosphere in place behind a departing low pressure system, areas of frost are expected late tonight through early Tuesday morning in colder wind sheltered locations in the valleys and some coastal canyons.
A frost advisory remains in effect from 10 pm this evening to 9 am Tuesday for colder wind sheltered locations.
Temperatures will fall into the upper 20s to mid 30s late tonight through early Tuesday morning.
A frost advisory means that frost is possible. Sensitive outdoor plants may be killed if left uncovered.