Long Island forecast: A wave of 'dangerous heat'

A wave of "dangerous heat" arrives Thursday, blanketing Long Island and the region in temperatures predicted to hit the low-to-mid-90s through Saturday, with a heat index in the triple digits, according to the National Weather Service.

It's forecast to be Long Island's warmest stretch of the summer so far and Thursday could turn out to be the hottest day of 2023 to date. Friday could be even hotter, the weather service said.

The heat index — which measures how hot it really feels after factoring in the humidity — will be about 100 degrees through Friday, the weather service said. The scorching temperatures will be accompanied by deteriorating air quality, and by late Thursday afternoon into the evening, a chance for some thunderstorm activity, forecasters said.

Dominic Ramunni, a weather service meteorologist based in Upton, said Thursday will have a heat index in the low 100s.

“I think we'll do that again on Friday, maybe a couple degrees warmer and could get close to 105,” Ramunni said of the heat index. “As you get closer to the city, the heat index might bounce between 100 and 110 at times. It's dangerous heat.”

Saturday will bring only mild relief, with the heat index remaining in the high 90s in most locations before temperatures return to the low 80s on Sunday.

Meanwhile, an air quality health advisory, which had been in place for Long Island and the metropolitan region on Wednesday, has been extended through Thursday because of ozone pollution concerns related to the heat, state officials said.

The intense heat, health experts said, brings the risk of serious related illnesses, particularly for vulnerable populations such as young children, the elderly, pregnant women and those with chronic ailments.

“The key is to drink a lot of fluids if you have to be outside” said Dr. Kerry Frommer Fierstein, chief executive of Allied Physicians Group and a pediatrician based in Plainview. “If you are doing physical activity, take frequent breaks. And if you are not feeling well, like you have a fever or are getting dizzy, go inside.”

PSEG Long Island said it has enough electric capacity to meet projected peak demand during the upcoming heat wave.

"We have been upgrading equipment, carefully planning to provide sufficient electric capacity to meet peak demand, and positioning our personnel to respond effectively if needed,” said Michael Sullivan, the utility's vice president of electric operations.

Gov. Kathy Hochul urged New Yorkers to remain indoors, whenever possible, in air-conditioned settings.

"This is extreme even for some of the parts of our country where we're seeing these numbers, but for New York State, this is highly unusual," Hochul said during a press briefing in upstate New York Wednesday. 

State parks will extend swimming hours on Thursday and Friday for an additional hour, officials announced.

On Long Island all Jones Beach, Robert Moses and Sunken Meadow fields will remain open to swimming until 8 p.m. Heckscher, Hither Hills, Orient Beach and Wildwood will remain open until 7 p.m. and Montauk Downs Pool will remain open until 6:30 p.m.