A frost advisory for Wednesday night into Thursday has been issued by the National Weather Service.
The advisory, which means frost is possible, is in effect from 10 p.m. Wednesday until 9 a.m. in areas of Southern California including Riverside County valleys, where temperatures in some areas may fall into the low 30s and upper 20s, according to NWS.
Clear skies and an overnight temperature of 25 degrees were forecast for Temecula and Murrieta.
"..Air mass over the region is very dry and temperatures will fall rapidly after sunset tonight and again Thursday night..." NWS stated in the advisory.
Temperatures could drop below freezing by 10 p.m., weather officials said.
The freezing temperatures and frost are likely to cause damage to sensitive outdoor plants left uncovered, weather officials said.