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.

Light Rain

40°F

4°C

Humidity 83%
Wind Speed NW 10 mph
Barometer 29.75 in (1007.6 mb)
Dewpoint 35°F (2°C)
Visibility 6.00 mi
Wind Chill34°F (1°C)
Last update 12 Mar 2:56 pm EDT
Extended Forecast for

North Great River NY

  • This Afternoon

    This Afternoon: Rain and snow. Steady temperature around 39. Northwest wind around 17 mph. Chance of precipitation is 90%. Total daytime snow accumulation of less than a half inch possible.

    High: 39 °F

    Rain/Snow

  • Tonight

    Tonight: Snow before 10pm, then a slight chance of rain between 10pm and 11pm. Low around 30. West wind 7 to 9 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.

    Low: 30 °F

    Rain/Snow
    then Mostly
    Clear

  • Friday

    Friday: Increasing clouds, with a high near 46. Light and variable wind becoming south 9 to 14 mph in the morning.

    High: 46 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 36. South wind 10 to 13 mph, with gusts as high as 32 mph.

    Low: 36 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 49. West wind 14 to 16 mph, with gusts as high as 31 mph.

    High: 49 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 32.

    Low: 32 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 48.

    High: 48 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Rain, mainly after 2am. Low around 39. Chance of precipitation is 80%.

    Low: 39 °F

    Chance Rain
    then Rain

  • Monday

    Monday: Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.

    High: 56 °F

    Rain and
    Breezy

Detailed Forecast

This Afternoon
Rain and snow. Steady temperature around 39. Northwest wind around 17 mph. Chance of precipitation is 90%. Total daytime snow accumulation of less than a half inch possible.
Tonight
Snow before 10pm, then a slight chance of rain between 10pm and 11pm. Low around 30. West wind 7 to 9 mph. Chance of precipitation is 80%. New snow accumulation of less than a half inch possible.
Friday
Increasing clouds, with a high near 46. Light and variable wind becoming south 9 to 14 mph in the morning.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 36. South wind 10 to 13 mph, with gusts as high as 32 mph.
Saturday
Sunny, with a high near 49. West wind 14 to 16 mph, with gusts as high as 31 mph.
Saturday Night
Increasing clouds, with a low around 32.
Sunday
Mostly cloudy, with a high near 48.
Sunday Night
Rain, mainly after 2am. Low around 39. Chance of precipitation is 80%.
Monday
Rain and possibly a thunderstorm. High near 56. Breezy. Chance of precipitation is 100%.
Monday Night
Rain, mainly before 2am. Low around 34. Breezy. Chance of precipitation is 80%.
Tuesday
A 30 percent chance of rain. Mostly sunny, with a high near 44.
Tuesday Night
Partly cloudy, with a low around 24.
Wednesday
Sunny, with a high near 38.
Wednesday Night
Partly cloudy, with a low around 28.
Thursday
Mostly sunny, with a high near 42.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
North Great River NY
 40.74°N 73.16°W (Elev. 7 ft)
Last Update:
2:45 pm EDT Mar 12, 2026
Forecast Valid:
3pm EDT Mar 12, 2026-6pm EDT Mar 19, 2026
 
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