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 until 9 p.m. Wednesday.

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.

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

Highs lingered in the upper 80s and lower 90s Tuesday with temperatures expected to climb Wednesday with high humidity. 

The temperatures are expected to peak between 11 a.m. and 5 p.m., according to the weather service. 

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.

Complicating matters, smoke from the Canadian wildfires in Ontario made for hazy conditions Tuesday and could linger through Wednesday and Thursday, according to the weather service. Forecasters warn the smoke could affect air quality and visibility. 

There may be a slight chance of showers and thunderstorms Wednesday evening. 

Meteorologist Bryan Ramsey said since the fires were not anticipated, "how long and how bad that will it be really will depend on how much of that smoke can make it to the surface."

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

Temperatures on Thursday may still be warm, but with lower humidity making temperatures feel like the low 90s, according to the forecast. 

Showers are expected to arrive by Friday evening and come with possible thunderstorms into the weekend. The rain is expected to remain through Sunday, according to the forecast. 

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 three cooling centers would be open from 9 a.m. to 4 p.m. during the advisory: Cantiague Park, 480 W. John St., Hicksville; Mitchel Field Athletic Complex, 1 Charles Lindbergh Blvd., Uniondale; and Wantagh Park, 1 King Rd., Wantagh.

The former Nassau County Family Court, 1200 Old Country Rd., 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., through Thursday, at Yes We Can Community Center,  141 Garden St., Westbury, and Clinton G. Martin Park, 1601 Marcus Ave., 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. 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 Wednesday.

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