The chances umbrellas will be needed on Wednesday are just 20% and that is after 3 p.m., the National Weather Service in Islip said.
However, any storms that do develop could bring "heavy rain and gusty winds," News 12 Long Island meteorologist Rich Hoffman said. The best chance for storms will be in Nassau County west toward New Jersey, he said.
But, Hoffman said, most of the day will be dry: "You can squeeze in beach time," he said.
Look for a daytime high of 83 degrees. And any nighttime showers should clear off in time for a sunny Thursday, the experts said.
After that, a Friday to Saturday damp stretch could set in, but the odds of a wet Sunday then decline to just 30% after midday.
Before that, air conditioning could be a boon, especially inland.
"Temperatures on Thursday are forecast to rise to the upper 80s and lower 90s," the weather service said. "Heat index values should reach the mid- and upper 90s across the interior and the lower 90s elsewhere."
Friday could begin with some fog before 8 a.m. and possible downpours, with the odds of storms rising to the “likely” category after noon, the weather service said.
The daytime high will be in the low to mid-80s, just like on Saturday, when showers also are likely — but before midday. Storms might lift away Saturday afternoon, though the odds rain will fall are 60%, the weather service said.
Sunday storms might hold off until after noon, when the odds of storms slide to 30%. The high temperature Sunday will be 85 degrees.
Monday should be just as warm but sunny. Showers may return Tuesday, when highs in the low 80s are expected, the weather service said.