Saturday's highs, expected to be in the 80s across most of Long Island, are forecast to drop to the low to mid 70s before the evening running of the Belmont Stakes, the National Weather Service said.
And with mostly clear skies, temperatures will remain seasonable for the weekend, the service said.
"The weekend in general should be tranquil," said Joe Pollina, a meteorologist based in the service's Upton office. "It's a pretty quiet weather weekend."
Temperatures in much of Nassau County will reach the upper 70s and low 80s on Saturday, with cooler temperatures on the Twin Forks, Pollina said.
Overnight temperatures in much of Nassau and western Suffolk counties will drop to the low 60s. Eastern Long Island will see temperatures in the mid 50s, Pollina said.
Light winds and clear skies will allow for cooler conditions out in the pine barrens, Pollina said.
Sunday will be slightly warmer, with highs in the low 80s for much of Long Island and lows in the upper 50s and lows 60s, Pollina said.
Monday will be mostly dry, with a 30 to 40 percent chance of precipitation in Nassau, and a 25 to 35 chance of precipitation in Suffolk.
Race time for the 146th running of the Belmont Stakes is 6:52 p.m.