Heat Dome Brings 100+ Temps To NYC Ahead Of July 4th Weekend

NEW YORK CITY — A heat dome is settling over the five boroughs, bringing scorching triple-digit temperatures and severe heat warnings ahead of the July 4th weekend, forecasters said.

Daytime temperatures will approach 100 degrees beginning Wednesday, triggering an Extreme Heat Warning as well as an Air Quality Alert from the National Weather Service.

On Wednesday, the temperature will feel even hotter than the thermometer reads, with heat index values between 100 and 105 degrees, despite the 20 percent chance of rain in the afternoon.

The heat dome, a large-scale weather pattern that acts like a lid on a pot of boiling water, traps heat over an area for a week or more.

The heat dome will keep temperatures in the low 100s through Thursday, with the "feels like" temperature between 103 and 108 degrees, according to the National Weather Service.

Three-digit heat index values are expected to persist through Friday and Saturday, when the country will celebrate the 250th anniversary of Independence Day. Along with the brutal heat, Friday and Saturday will both see around a 20 to 40 percent chance of showers and thunderstorms, which may offer short-lived relief.

"We’re staring down what could be the second hottest day in New York City history in over a decade — and City government is taking historic measures to keep all New Yorkers indoors, cool and safe," said Mayor Zohran Mamdani.

The last 100-degree day recorded in Central Park was July 18, 2012, according to AccuWeather.

"Stay inside, look out for your neighbors, drink plenty of water and watch out for signs of heat exhaustion such as confusion, nausea and trouble breathing," Mamdani said.

Cooling centers will open across the five boroughs, and officials are urging New Yorkers to stay hydrated, limit outdoor activities during the hottest part of the day, monitor weather forecasts and check on New Yorkers with health risks.

Air-conditioned, city-owned and operated vans will also be making the rounds in the city, bringing life-saving relief from the heat to the most vulnerable New Yorkers, Mamdani said. These vans will be equipped with medical staff, water, electrolytes, sunscreen and more.

"While temperatures during the day will be dangerous, the lack of any relief from the heat and humidity at night can be especially stifling and even deadly, especially for those that don't have air conditioning," AccuWeather expert meteorologist Matt Benz said.

Here's the latest forecast from the National Weather Service.

Tuesday: Mostly sunny, with a high near 90. Light southwest wind becoming south 5 to 9 mph in the morning.

Tuesday night: A 20 percent chance of showers and thunderstorms after 11 p.m. Partly cloudy, with a low around 74. Southwest wind around 9 mph, with gusts as high as 21 mph.

Wednesday: A 20 percent chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 96. Heat index values as high as 104. Southwest wind around 8 mph.

Wednesday Night: Mostly clear, with a low around 79. Southwest wind 5 to 7 mph.

Thursday: Sunny and hot, with a high near 101. West wind around 6 mph.

Thursday night: Clear, with a low around 84.

Friday: A 30 percent chance of showers after 2 p.m. Increasing clouds and hot, with a high near 101.

Friday night: A 30 percent chance of showers before 8 p.m. Partly cloudy, with a low around 80.

Saturday: A 40 percent chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 99.

Saturday night: A chance of showers and thunderstorms before 8 p.m., then a chance of showers between 8 p.m. and 2 a.m. Mostly cloudy, with a low around 76. Chance of precipitation is 40 percent.

For questions, email Miranda.Levingston@Patch.com.