Long Island Weather: 110-Degree Heat Index Sunday Then Storms

Sunday will be another dangerously hot day on Long Island, but there is some relief on the way.

An excessive heat warning is in effect Sunday until 8 p.m. for Suffolk County and 9 p.m. for Nassau County. High temperatures will be in the mid-90s, but with the humidity factored in, the heat index could reach 110 degrees on parts of the island, the National Weather Service says. Cooling centers are open across the island.

There's a chance of showers and thunderstorms Sunday night, but it's the heavy rain and storms coming Monday that will finally break the heat.

A hazardous weather outlook has been issued for the entire island as flash flooding will be possible Monday afternoon through early Tuesday. A flash flood watch will be in effect in Nassau County from noon Monday until 8 a.m. Tuesday.

Thunderstorms will be capable of producing heavy rainfall and multiple rounds of these
thunderstorms with heavy rain will be possible, the NWS says.

High temperatures on Monday will be much more seasonable in the low-80s.