A very cold dry air mass sat over Southern California today, prompting meteorologists to issue a frost advisory for the Inland Empire.
Light winds amid mostly clear skies combined with the cold air mass to allow temperatures into the lower and mid-30s across parts of the Inland Empire, according to the National Weather Service. The agency set the frost advisory to expire at 9 a.m.
"This cold weather may damage sensitive plants or animals," an NWS advisory said.
The frost advisory covered valley areas around Riverside and parts of San Bernardino County.Expect frost tonight as well. According to the NWS, patchy frost is forecast after 10 p.m. in Southwest Riverside County with an overnight low around 33. Forecasters are predicting a west wind 5 to 10 mph becoming light and variable in the evening.
Friday morning in Southwest Riverside County there will be patchy frost before 10 a.m. Otherwise, mostly sunny, with a high near 53, with a north wind 5 to 15 mph becoming south in the afternoon. Winds could gust as high as 20 mph.
Showers are likely beginning early Saturday morning in Southwest Riverside County, with a 60 percent chance of precipitation, increasing to 90 percent as the day goes on and a high temperature of just 51 degrees, according to the NWS.
Skies will clear Sunday but expect frost again before 10 a.m.