Long Island weather forecast: Temperatures to dip, rise, then drop again

Long Islanders can expect temperatures to dip over the next couple of days, rise into the 80s and drop back down this weekend, the National Weather Service said.

Temperatures were “right around normal” in the upper 70s for late summer on Monday, meteorologist James Tomasini with the weather service’s Upton office said. High temperatures will reach mid-70s on Tuesday and crater in the low 70s Wednesday, the weather service forecast. On Thursday, temps will reach the upper 70s and climb into the low to mid-80s on Friday.

High temperatures will then plunge back to around 70 across the Island on Saturday because a high-pressure system is “coming down from Canada with some cooler and drier air,” Tomasini said.

“It will start building late Friday night into Saturday,” the meteorologist said. “It will be here for the weekend, and then it looks like we will get a little bit warmer again starting Monday.”

Long Island is “abnormally dry,” according to the U.S. Drought Monitor. Due to a rainfall shortage, the New York State Department of Environmental Conservation has held Nassau and Suffolk counties under a drought watch, the lowest of four advisory levels, for several weeks.

Just over 13 inches of rain is considered the normal rainfall amount the weather service registers in Islip each June 1 through Sept. 30, according to the agency’s records dating back to 1963. Since June 1 of this year, only 9.29 inches of rain have been recorded at Islip.

The National Weather Service has forecast a 60% chance of showers and thunderstorms from Tuesday evening into Wednesday and a 30% chance of showers on Thursday.

“We are expecting pretty light rainfall," Tomasini said. "Only about up to a quarter of an inch maybe across Long Island."