Long Island weather: Partly sunny, seasonably warm

Sunday's showers and thunderstorms overnight are forecast to give way to a partly sunny Monday across Long Island, with a high of 73 degrees, according to the National Weather Service.

A cold frontal passage Sunday evening is to bring temperatures back close to normal for this time of year for Monday, the weather service said.

"There's some activity tonight, tomorrow it cools down," said James Connolly, a meteorologist with the weather service. 

The average high temperature for Islip for May 23 is 70 degrees, based on the weather service's 30-year average normals, Connolly said.

The thermometer reached a high of 84 degrees just after 11 a.m. Sunday in Islip.

Monday's nighttime weather is to be mostly cloudy with a low around 56 degrees, and Tuesday is also forecast to be partly sunny, with Wednesday mostly cloudy.

Temperatures will keep dropping Tuesday — to 66 degrees, according to the forecast. Friday will return to the lower to mid-70s.

By Matthew Chayes

matthew.chayes@newsday.comchayesmatthew

Matthew Chayes, a Newsday reporter since 2007, covers New York City.