Bill and Christine DeWitt, of West Islip, and their children,...

Bill and Christine DeWitt, of West Islip, and their children, Billy, 6, and Caitlin, 4, collect shells at Robert Moses State Park on Sunday, Nov. 30, 2014. Credit: James Carbone

Long Islanders can expect warmer, mild temperatures for most of the week, except for a cool down and chance of rain and light snow Tuesday, according to the National Weather Service in Upton.

"It looks like an up and down kind of week," Meteorologist Joe Pollina said. "Some days will be warmer than others."

Temperatures shot up nearly 20 degrees Sunday morning into the low 50s in most towns. Partly sunny skies and highs in the 50s are forecast for Sunday and Monday, the weather service said.

But temperatures are expected to plummet again Monday night into the 30s with wind chills in the low 20s. Cooler temperatures on Tuesday could come with a mixture of rain and snow, but not with any snow accumulation on the ground, Pollina said.

Rain may continue through Wednesday, with temperatures warming again into the 50s. Highs will linger in the mid 40s heading into the weekend, with another chance of rain Friday.

Get the latest news and more great videos at NewsdayTV Credit: Newsday

After 47 years, affordable housing ... Let's Go: Williamsburg winter village ... Get the latest news and more great videos at NewsdayTV

Get the latest news and more great videos at NewsdayTV Credit: Newsday

After 47 years, affordable housing ... Let's Go: Williamsburg winter village ... Get the latest news and more great videos at NewsdayTV

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