Rain is possible early Saturday but the skies are expected to start clearing and stay mostly cloud-free until Tuesday night.
The National Weather Service on Friday night said there was a 30% chance of showers before 2 p.m. Saturday on Long Island with a high temperature near 77 degrees, which would be 6 degrees below the normal high for the date in Islip. A northwest wind of around 8 mph should shift to a southeast wind in the afternoon.
Saturday is the first full day of the three-day Muslim festival of Eid al-Adha.
It is expected to be partly cloudy Saturday night, with a low temperature of around 63 degrees.
Sunday will bring sunny skies and a high temperature near 79 degrees, the weather service said.
There is a moderate risk of rip currents off Long Island's ocean beaches on both Saturday and Sunday, according to the weather service.
Monday and Tuesday should also be sunny before Tuesday night brings a 30% chance of showers and thunderstorms.
There is also a chance of showers and thunderstorms Wednesday after 2 p.m. but Thursday and Friday are expected to be at least partly sunny.
High temperatures during the Monday to Friday workweek will range from the mid to high 80s, the weather service said.