Long Island weather: More heat and humidity on the way

Sunday's isolated thunderstorms brought a much-needed cool down to Long Island but another round of high heat, stifling humidity and mostly sunny skies is in the forecast through Wednesday, according to the National Weather Service.

A heat advisory begins Monday at 11 a.m. and continues until 8 p.m. Wednesday, the weather service said.

"A Heat Advisory is issued when the combination of heat and humidity is expected to make it feel like it is 95 to 99 degrees for two or more consecutive days, or 100 to 104 degrees for any length of time," according to a statement on the weather service's website.

Monday's high is forecast to climb to 90. The evening will cool to about 73. Tuesday and Wednesday will be hotter, with a high near 93 Tuesday and 92 Wednesday. In the evening, the low is forecast to be in the mid-70s.

The heat index value will reach into the upper 90s, according to the weather service. 

"Seniors and those with chronic health problems or mental health conditions are at an increased risk," the heat advisory says. "Homes without air conditioning can be much hotter than outdoor temperatures. Use air conditioning to stay cool at home or go to a place that has air conditioning."

On Wednesday night, there’s a 40% chance of showers.

"After Wednesday, we are expecting a significant drop-off in temperature," said David Stark, a meteorologist with the weather service's Upton office.

Thursday "will be a lot more comfortable," Stark said, with a high around 84 and a 50% chance of rain.

There's a 30% chance of rain Friday, according to the weather service, but next weekend looks to be mostly clear with daytime highs about 82 and dipping to the mid 60s in the evening.