Friday was hottest day of year, but temps to drop over weekend, weather service says

If it felt like the hottest day on Long Island was Friday, there may be a reason.

Temperatures across the region hit a high of 91 degrees — just shy of 2016 record of 93 degrees — but hot enough to rank as the warmest day of 2021, according to the National Weather Service in Upton.

"And with all of this is the humidity making it feel much hotter," added Dominic Ramunni, a National Weather Service meteorologist.

But relief is on the way with Friday night storms and cooler Saturday temperatures in the forecast.

Friday's excruciating heat and humidity made for an uncomfortable day across the region, with a heat index topping 100 degrees on parts of the Island and New York City, according to the weather service.

LIPA for the first time in 20 years asked ratepayers across Long Island and the Rockaways to curtail "all non-essential" energy use as it projected peak energy use in response to Friday’s heat while dealing with the outage of two major power lines to Long Island, and half-capacity at a third.

The day saw the Long Island territory exceed PSEG Long Island’s expected peak for the day of 5,100 megawatts, hitting a high of 5,126 megawatts. However, the system had experienced no major outages by 5:30 p.m. Friday.

As reported Wednesday, LIPA and PSEG enacted demand-reduction measures and were resorting to smaller power plants it had planned to retire to help make up the gap for problems at the three cables, including one called Y-49 owned by the New York Power Authority that has seen numerous failures — four in the past year.

PSEG sent an alert to customers asking them to raise thermostats on air conditioners or use fans instead, and to wait until after 7 p.m. to run dishwashers, pool pumps and washing machines.

Nassau County, meanwhile, opened cooling centers in Hicksville, Uniondale and Wantagh to help residents beat the heat and extended pool hours at Wantagh, Cantiague Park and Nickerson Beach until 7 p.m.

Additionally, an air quality alert for New York City and Long Island was in effect all day Friday, according to the State Department of Environmental Conservation. High levels of lung-burning ozone, the primary component of smog, were anticipated.

But potential thunderstorms Friday evening were expected to bring relief, particularly for the western portions of the area, the weather service said.

"Heavy rainfall is possible with any showers and thunderstorms through Saturday," the weather service said.

Temperatures are expected to be slightly cooler Saturday, in the upper 80s, while the potential for storms is at 50%, said James Connolly, a weather service meteorologist.

The high pressure system sitting off the Atlantic, whose clockwise circulation is pulling heat and humidity up from the south, should give way to a cold front sweeping in from the west on Saturday, the weather service added.

"[Saturday] will still be hot but after the front comes through it will cool off," Connolly said.

Heat indexes Saturday should not rise higher than the low 90s, the weather service said, predicting skies will clear "into the evening and overnight" as the cold front delivers drier air.

"Low temperatures Saturday night will drop into the 60s with warmer spots near the NYC metro, about average for this time of year," the weather service said.

Sunday starts a triple play through Tuesday: those three days all should be at least partly sunny, according to the weather service, with daytime highs of 79 or 80, and nighttime lows in the mid- to upper 60s.

The odds of rain run from 30% to 40% on Wednesday and Thursday, when temperatures again should stay in those same ranges.

By Robert Brodsky

robert.brodsky@newsday.com,joan.gralla@newsday.com@BrodskyRobert,

Robert Brodsky is a breaking news reporter who has worked at Newsday since 2011. He is a Queens College and American University alum.