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A taste of fall before a soggy stretch settles in

Get outside and enjoy the comfortable tonight and tomorrow before the rain moves in on Sunday!

Nick Kosir

Sep 18, 2026, 6:45 PM

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Islip Information

Islip Information

Islip, New York • Climate data: Islip MacArthur Airport (ISP)
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Cool and Dry Evening Ahead

Cooler, drier air will move in behind today’s cold front. Humidity will drop through the afternoon and evening, making for a much more comfortable feel. By Saturday morning, temperatures will drop into the mid- to upper 50s.

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Saturday will be a cooler day, where temperatures may struggle to reach the upper 60s. An easterly breeze and increasing clouds will help keep temperatures down.

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Heavy Rain Possible Sunday

A warm front will approach Saturday night, bringing increasing humidity and a chance for rain by late Sunday morning.

Rain could become steadier and heavier Sunday afternoon and evening. Some areas could see locally heavy downpours, and there is a risk of isolated flash flooding, especially if heavy rain falls over the same areas for an extended period.

Exactly where the heaviest rain will fall is still uncertain, so the forecast may change as Sunday gets closer.

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Cooler and Unsettled Weather Next Week

The front should move south of the area Monday, bringing another stretch of cooler weather.

Monday could be mostly dry, although a few light showers are possible depending on how far south the front moves.

Cool, cloudy conditions are expected to continue through at least Wednesday, with temperatures running below average for this time of year.

By the middle and end of next week, another storm system could develop offshore, bringing more clouds and additional rain chances. The exact timing and location of the rain remain uncertain because forecast models are not yet in agreement.

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