Long Island weather: Heat advisory extended for most of the region; heat index near 100

The National Weather Service extended its two-day heat advisory to include eastern Long Island, with heat index values reaching the lower 100s.

Long Island should expect hot and humid conditions during the advisory, which is in effect from 11 a.m. Tuesday until 9 p.m. Wednesday.

A high risk of rip currents is possible at ocean beaches on Tuesday and Wednesday, the service said.

In a morning briefing, the service said heat index values on Tuesday would reach the upper 90s for most of Nassau County and parts of northwestern Suffolk.

Areas along the South Shore will feel slightly cooler with values in the lower 90s and upper 80s, while the East End will see values in the upper 70s.

Wednesday will be the hottest day of the week with heat index values reaching the lower 100s for the majority of Long Island, including a forecast of real-feel temperatures of 102 degrees in Syosset, 101 degrees in Stony Brook, and 100 degrees in Islip.

While the weather service forecasts a heat index of 100 in Riverhead; areas to its east will feel cooler with values in the upper 80s.

Smoke from a wildfire outbreak in Ontario could potentially reduce visibility and air quality on Wednesday, the National Weather Service said. 

Meteorologist Bryan Ramsey said since the fires were not anticipated, it was too soon to tell how it may affect Long Island. 

But if there is enough smoke, it would travel to Long Island by Wednesday evening.

"How long and how bad that will it be really will depend on how much of that smoke can make it to the surface," Ramsey said. 

Enough smoke in the air also can produce "really glowing red and orange sunrises and sunsets," he said. 

The extreme weather will break by Wednesday night, allowing "very warm but less humid conditions for Thursday and Friday," forecasters said.

The service encouraged those outside during the advisory to drink plenty of water and avoid alcohol, apply sunscreen every two hours, wear lightweight, light-colored loose-fitted clothing, and take regular breaks in the shade to prevent heat-related illnesses.

Nassau County said on its website that three cooling centers would be open from 9 a.m. to 4 p.m. during the advisory: Cantiague Park at 480 W John St. in Hicksville; Mitchel Field Athletic Complex at 1 Charles Lindbergh Blvd. in Uniondale; and Wantagh Park at 1 King Rd in Wantagh.

The former Nassau County Family Court at 1200 Old Country Rd. in Westbury will be open for cooling around the clock.

The Town of North Hempstead announced it will open two cooling centers, 10 a.m. to 6 p.m., Tuesday through Thursday, at the Yes We Can Community Center at 141 Garden St. in Westbury and the Clinton G. Martin Park at 1601 Marcus Ave. in New Hyde Park.

North Hempstead pools and beaches will also have extended hours: the Manorhaven Beach Park Pool in Port Washington and Harbor Hills Pool in Harbor Hills are open 10 a.m. to 9 p.m. while the Whitney Pond Park Pool in Manhasset and the Martin "Bunky" Reid Park Pool in Westbury are open 10 a.m. to 8 p.m.

Town spray pads at North Hempstead parks will remain open until 9 p.m., Tuesday through Thursday. 

North Hempstead Beach Park in Port Washington will also remain staffed with lifeguards until 8 p.m. through Thursday. 

The Town of Hempstead plans to extend beach and pool hours, according to a news release.

Suffolk County residents can view the county website for a full list of activated cooling facilities.

In addition, the Town of Riverhead announced beach facilities would have extended hours until 9 p.m., and lifeguards and attendants would be present from 11 a.m. to 6 p.m. on Tuesday and Wednesday.

The town Senior Center also will be open 8 a.m. to 4 p.m. on Tuesday and Wednesday as a cooling center, a news release said.