New year, new weather — chilly temperatures and sun are replacing the warm temperatures and cloudy skies of December.

The high for Saturday is expected to be a seasonal 40 degrees, with a low around 30, said Faye Barthold, a meteorologist with the National Weather Service’s Upton office. Sunday will be slightly warmer at 43 degrees.

advertisement | advertise on newsday

There may be some wind, Barthold said, but conditions will remain normal for January until Sunday night, when the cold air moves in.

Photos25 things every LIer must do this winter on LIPhotosWeird weather on Long Island

Lows overnight into Monday will register around the mid 20s, and highs to start out the week won’t top the lower 30s, she said.

“Monday we get the really cold air,” Barthold said. “We might not break freezing, and it’ll be even colder on Tuesday.”