SAN DIEGO - A frost advisory was in effect early Tuesday in the valleys of San Diego County.
The National Weather Service scheduled the frost advisory until 8 a.m., saying temperatures were likely to dip into the lower to mid-30s in many areas and briefly into the mid- to upper 20s in wind-sheltered valleys.
"A frost advisory means that frost is possible," according to an NWS advisory. "Measures should be taken to protect crops and plants. Sensitive vegetation may be killed if left uncovered."