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

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

75°F

24°C

Humidity 42%
Wind Speed E 10 mph
Barometer 30.13 in (1020.3 mb)
Dewpoint 50°F (10°C)
Visibility 10.00 mi
Last update 13 Jun 2:56 pm EDT
Extended Forecast for

North Great River NY

  • Tonight

    Tonight: A chance of showers and thunderstorms between 2am and 5am, then showers likely and possibly a thunderstorm after 5am. Mostly cloudy, with a low around 60. East wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 60 °F

    Mostly Cloudy
    then Showers
    Likely

  • Saturday

    Saturday: Showers and possibly a thunderstorm before noon, then a chance of rain, mainly between noon and 5pm. High near 66. Northeast wind 9 to 11 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    High: 66 °F

    Showers then
    Chance Light
    Rain

  • Saturday Night

    Saturday Night: A 30 percent chance of light rain, mainly between 8pm and 2am. Cloudy, with a low around 57. Northeast wind 8 to 10 mph.

    Low: 57 °F

    Chance Light
    Rain

  • Sunday

    Sunday: A slight chance of light rain before 11am, then a slight chance of light rain after 2pm. Mostly cloudy, with a high near 67. East wind around 10 mph. Chance of precipitation is 20%.

    High: 67 °F

    Slight Chance
    Light Rain

  • Sunday Night

    Sunday Night: A slight chance of rain or light rain before 8pm, then a chance of rain, mainly after 2am. Mostly cloudy, with a low around 59. East wind 3 to 6 mph. Chance of precipitation is 30%.

    Low: 59 °F

    Chance Rain

  • Monday

    Monday: A 30 percent chance of rain. Mostly cloudy, with a high near 68.

    High: 68 °F

    Chance Rain

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 59.

    Low: 59 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 74.

    High: 74 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 63.

    Low: 63 °F

    Mostly Cloudy

Detailed Forecast

Tonight
A chance of showers and thunderstorms between 2am and 5am, then showers likely and possibly a thunderstorm after 5am. Mostly cloudy, with a low around 60. East wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday
Showers and possibly a thunderstorm before noon, then a chance of rain, mainly between noon and 5pm. High near 66. Northeast wind 9 to 11 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Saturday Night
A 30 percent chance of light rain, mainly between 8pm and 2am. Cloudy, with a low around 57. Northeast wind 8 to 10 mph.
Sunday
A slight chance of light rain before 11am, then a slight chance of light rain after 2pm. Mostly cloudy, with a high near 67. East wind around 10 mph. Chance of precipitation is 20%.
Sunday Night
A slight chance of rain or light rain before 8pm, then a chance of rain, mainly after 2am. Mostly cloudy, with a low around 59. East wind 3 to 6 mph. Chance of precipitation is 30%.
Monday
A 30 percent chance of rain. Mostly cloudy, with a high near 68.
Monday Night
Mostly cloudy, with a low around 59.
Tuesday
Mostly cloudy, with a high near 74.
Tuesday Night
Mostly cloudy, with a low around 63.
Wednesday
Partly sunny, with a high near 79.
Wednesday Night
Mostly cloudy, with a low around 67.
Juneteenth
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 83.
Thursday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 68.
Friday
Mostly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
North Great River NY
 40.77°N 73.15°W (Elev. 30 ft)
Last Update:
3:03 pm EDT Jun 13, 2025
Forecast Valid:
3pm EDT Jun 13, 2025-6pm EDT Jun 20, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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