Mother Nature appears to be OK with Memorial Day being the unofficial start of summer.

The Long Island forecast for the day after the extended holiday weekend is for mostly sunny skies and high temperatures near 80 degrees, giving way to a stretch of unseasonably warm conditions for the week, the National Weather Service said Tuesday.

The service's Upton office said Tuesday's highs will be almost 10 degrees above normal; daily highs through the week are likely to be about 5 degrees or higher above normal.

News 12 Long Island meteorologist Samantha Augeri said a passing warm front north of Long Island is responsible for Tuesday's summerlike conditions.

"So now we have warm, humid air in place with a southerly wind," she said. "The North Shore continues to be the hot spot with temps maybe as warm as 83 in Nassau."

Along with the temperature, humidity levels also will rise, reaching into the mid 80s.

advertisement | advertise on newsday

Tuesday night, clouds increase and patchy fog is likely into Wednesday morning.

There's a slight chance for showers and thunderstorms before 9 a.m. Wednesday, along with the fog.

Daily highs in the mid to low 70s with a south wind from 10 to 17 mph are likely.

Chance of rain overall Wednesday is 20 percent, the service said.