Long Island Weather: Sweltering Heat Coming With Triple Digit Index

LONG ISLAND, NY — The heat wave that's blanketed Long Island won't let up any time soon.

The heat index could reach 98 Monday and into the triple digits, as high as 101 degrees in Islip Tuesday, according to the National Weather Service.

Hot and humid conditions likely will continue through the early week because of an offshore high pressure system known as a Bermuda high, meteorologists say.

"Nighttime conditions on Long Island will hit mid-70s, lower than during the daytime hours," according to Vinny Vozzollo, of the National Weather Service Office in Upton.

And the muggy conditions could get worse before they get better.

Showers and thunderstorms predicted late Monday and into Tuesday will only bring more moisture to the Northeast, according to AccuWeather.

Potential downpours followed by sunny weather will create steamy weather, AccuWeather reported.

But cooler air will likely arrive Wednesday, though storms could linger. AccuWeather predicted highs in the low- to mid-80s.

"After some very warm days early this week, big changes in the weather pattern will allow cooler air to push southward into the Northeast as the week progresses," said Alex DaSilva, a long-range meteorologist with AccuWeather, in a report from the service.

"For many people in the Northeast, the cooldown will feel extreme since the past few weeks have been so warm and since humidity levels have been so high of late."

Here's the complete National Weather Service forecast.

Monday

A 20 percent chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 90. Heat index values as high as 97. South wind 13 to 15 miles per hour.

Monday night

Partly cloudy, with a low around 77. Southwest wind 9 to 14 miles per hour.

Tuesday
A 40 percent chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 92. Heat index values as high as 101. Southwest wind 10 to 13 miles per hour.

Tuesday Night

A 50 percent chance of showers and thunderstorms before 2 a.m. Mostly cloudy, with a low around 75. Southwest wind around 6 miles per hour becoming calm in the evening.

Wednesday

A chance of showers and thunderstorms between 8 a.m. and 2 p.m., then showers likely and possibly a thunderstorm after 2 p.m. Partly sunny, with a high near 85 degrees. North wind around 6 miles per hour becoming east in the afternoon. Chance of precipitation is 60 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Wednesday Night

Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 72. Chance of precipitation is 60 percent. New rainfall amounts between a quarter and half of an inch possible.

Thursday

A 40 percent chance of showers. Partly sunny, with a high near 85 degrees.

Thursday Night

Partly cloudy, with a low around 69 degrees.

Friday

Mostly sunny, with a high near 83 degrees.

Friday Night

Partly cloudy, with a low around 65 degrees.