A frost advisory was issued by the National Weather Service for early-morning hours Monday through Wednesday, the result of cold air from the north flowing into the Central Coast.

The weather service said overnight temperatures could drop into the high 20s to near freezing.

John Lindsey, a local meteorologist for PG&E, said lows in the North County will be near 30 each morning through Wednesday. Lows will be in the mid-30s in San Luis Obispo for the same period, Lindsey said.

Residents are advised to shelter any plants that might be affected by cold weather. Motorists also need to remember that black ice can form in spots where the sun does not warm the roadway.

A dry New Year’s Eve and New Year’s Day are forecast, with daytime temperatures countywide remaining below normal. Highs should reach just the mid-to-upper 50s, the NWS said, while Lindsey said highs could be near 60 in San Luis Obispo.