While the heat isn't expected to climb above 90 degrees again Thursday, it'll sure feel like it, Storm Team 4 says.
The high is forecast to reach 89 degrees in the five boroughs, but conditions will feel more like 95 to 100 degrees, extending the city's heat advisory through 8 p.m.
The day will be muggy and cloudy, with strong thunderstorms rolling through into the afternoon and evening, mostly between 4 and 8 p.m.
The stifling, wet weather follows a sweltering Wednesday for the tri-state as the heat climbed above the 90-degree mark for the second day in a row, according to Storm Team 4.
Highs reached 95 degrees in the city, making it the hottest day of the year. Oppressive humidity made it feel much, much hotter to the south and west of the city, with the heat index approaching 100 degrees.
The National Weather Service issued a heat advisory through 8 p.m. Thursday, and Mayor de Blasio urged New Yorkers to use air conditioning when they can, drink water at regular intervals and limit strenuous activity, especially during the hottest parts of the day. Cooling centers were also open all across New York City and free outdoor pools will be open an hour later.
De Blasio added, however, that everyone needs to do their part to conserve energy, and said he was setting thermostats to 78 degrees in City Hall and other city buildings.
A power outage hit the 120-bed Advanced Care nursing home in Wayne, New Jersey, Wednesday afternoon, and while it wasn't immediately clear whether the heat played a role, the staff there said it took extra precautions to ensure the patients were safe from the temperatures and humidity.
Also, at least two areas in Brooklyn experienced power outages early Wednesday. Con Edison says outages in Park Slope on Union Street near Fifth Avenue and in Crown Heights between Kingston and Troy Avenues and Eastern Parkway and Carroll Street were most likely heat-related.
"It was awful," said Henry Burns, who was among the roughly 800 Crown Heights resident who were without power overnight. "I think I was sweating the whole night."
Nearby, Precious Gems Daycare owner Melvin Simmons had to turn kids away because of the outage.
"My lights aren't on, my gas is not on, the A/C is not on. It's very hot. We can't have the kids outside in this heat," said Simmons.
The outages weren't nearly as widespread as the ones last week that knocked out power to thousands of Staten Island customers. Con Edison spokesman Mike Clenendin attributed that to "problems that we corrected," saying Tuesday, "We should be OK heading into this heat wave."
Engineers are keeping a close eye on the power grid as Clenendin urged customers to manage energy as best they can.
"We're not looking to break a record," he said.
At 5 p.m. Wednesday, Con Ed recorded a power usage of 12,059 megawatts among its customers in New York City and Westchester. The all-time record happened on July 19, 2013, when Con Ed customers were using 13,200 megawatts at 5 p.m. Each megawatt powers about 1,000 homes.
On Tuesday, temperatures climbed as high as 94 degrees in New York City, with parts of the suburbs getting even hotter. With the humidity, it felt like more than 100 degrees in some spots.
Temperatures will be back above 90 by the end of the week.
-- Andrew Siff and Sheldon Dutes contributed to this report