National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

A Few Clouds

64°F

18°C

Humidity 43%
Wind Speed Vrbl 5 mph
Barometer 30.19 in (1022.2 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 15 Oct 3:56 pm EDT
Extended Forecast for

Great River NY

  • Tonight

    Tonight: Showers likely after 5am. Increasing clouds, with a low around 55. Southeast wind 7 to 13 mph. Chance of precipitation is 60%.

    Low: 55 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers before 2pm, then a slight chance of showers and thunderstorms after 5pm. High near 70. Southwest wind 15 to 18 mph. Chance of precipitation is 90%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 70 °F

    Showers then
    Chance
    Showers

  • Friday Night

    Friday Night: A slight chance of showers and thunderstorms, then showers after 8pm. Low around 48. Southwest wind 11 to 18 mph becoming northwest after midnight. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 48 °F

    Showers then
    Showers
    Likely

  • Saturday

    Saturday: Cloudy, then gradually becoming mostly sunny, with a steady temperature around 50. Breezy, with a north wind 20 to 22 mph.

    High: 50 °F

    Decreasing
    Clouds and
    Breezy

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 42. North wind 15 to 18 mph.

    Low: 42 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 57.

    High: 57 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 47.

    Low: 47 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 61.

    High: 61 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 49.

    Low: 49 °F

    Partly Cloudy

Detailed Forecast

Tonight
Showers likely after 5am. Increasing clouds, with a low around 55. Southeast wind 7 to 13 mph. Chance of precipitation is 60%.
Friday
Showers before 2pm, then a slight chance of showers and thunderstorms after 5pm. High near 70. Southwest wind 15 to 18 mph. Chance of precipitation is 90%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday Night
A slight chance of showers and thunderstorms, then showers after 8pm. Low around 48. Southwest wind 11 to 18 mph becoming northwest after midnight. Chance of precipitation is 90%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Saturday
Cloudy, then gradually becoming mostly sunny, with a steady temperature around 50. Breezy, with a north wind 20 to 22 mph.
Saturday Night
Mostly clear, with a low around 42. North wind 15 to 18 mph.
Sunday
Sunny, with a high near 57.
Sunday Night
Mostly clear, with a low around 47.
Monday
Sunny, with a high near 61.
Monday Night
Partly cloudy, with a low around 49.
Tuesday
Mostly sunny, with a high near 64.
Tuesday Night
Partly cloudy, with a low around 51.
Wednesday
Mostly sunny, with a high near 64.
Wednesday Night
Mostly clear, with a low around 49.
Thursday
Mostly sunny, with a high near 61.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Great River NY
 40.7°N 73.17°W (Elev. 7 ft)
Last Update:
2:36 pm EDT Oct 15, 2026
Forecast Valid:
4pm EDT Oct 15, 2026-6pm EDT Oct 22, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation