Long Island forecast: Heat advisory through Tuesday for LI

A heat advisory has been extended until Tuesday night for much of Long Island, a combination of temperatures and humidity that could cause heat-related illnesses, according to the National Weather Service.

Long Island is expected to experience a heat wave — defined at three consecutive days of 90 degrees or higher — based on readings at Islip, the representative location for the Island, according to weather service meteorologist Dave Radell, who is based at Upton.

The high Sunday was 90, he said; he forecasts that Monday’s high will be 93 and Tuesday’s 92. The temperatures are just shy of records for each day — which are 94 for Monday and 96 for Tuesday, both set in 1999, and 93 for Sunday, set in 2005.

“With high temperatures tomorrow in the low to mid 90s, combined with the humidity, it’s going to feel closer to 100 degrees outside,” he said Sunday. Similarly scorching conditions are forecast for Monday and Tuesday, he said.

“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors,” the weather service said in its heat advisory. “Young children and pets should never be left unattended in vehicles under any circumstances.”

The hot weather Sunday drove Long islanders to the beaches early. Robert Moses State Park had reached capacity and was closed to new visitors by 9:20 a.m., according to the state parks department. Jones Beach was closed by 11:50 a.m. Sunken Meadow State Park, Orient Beach State Park, Gilgo Beach and Hempstead Lake State Park also closed.

Tuesday brings a 30% chance of showers and thunderstorms. Wednesday through Saturday are predicted to be mostly sunny with less intense highs in the mid-to-upper 80s.

Nassau County’s cooling centers will be open through Wednesday, County Executive Laura Curran said. Public pools in Nassau will have extended hours.

Cooling centers:

• Cantiague Park Administration Office conference room, 480 W. John St., Hicksville,  from 10 a.m. to 8 p.m.
• Mitchel Field Administration Building, first floor, 1 Charles Lindbergh Blvd., Uniondale, from 10 a.m. to 6 p.m.
• Wantagh Administration Building community room, 1 King Rd., Wantagh, from 10 a.m. 6 p.m.

Pools with extended hours:

• Cantiague Park Pool, 480 W. John St., Hicksville, Saturday through Tuesday, from 10 a.m. to 7 p.m.
• Wantagh Park Pool, 1 King Rd., Wantagh, Saturday through Tuesday, from 10 a.m. to 7 p.m.

By Matthew Chayes

matthew.chayes@newsday.com,vera.chinese@newsday.comchayesmatthew,

Matthew Chayes, a Newsday reporter since 2007, covers New York City.