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

51°F

11°C

Humidity 69%
Wind Speed SW 8 mph
Barometer 30.12 in (1020.0 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Wind Chill48°F (9°C)
Last update 12 May 11:56 pm EDT
Extended Forecast for

North Great River NY

  • Overnight

    Overnight: Mostly cloudy, with a low around 50. Southwest wind around 9 mph.

    Low: 50 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, with a high near 64. Breezy, with a south wind 11 to 16 mph increasing to 19 to 24 mph in the afternoon. Winds could gust as high as 37 mph.

    High: 64 °F

    Mostly Cloudy
    then Mostly
    Cloudy and
    Breezy

  • Wednesday Night

    Wednesday Night: Showers likely, mainly after 2am. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 52. South wind 9 to 16 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 52 °F

    Chance
    Showers then
    Showers
    Likely and
    Patchy Fog

  • Thursday

    Thursday: Showers and possibly a thunderstorm. Patchy fog. High near 65. Southeast wind around 6 mph becoming calm in the morning. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 65 °F

    Showers and
    Patchy Fog

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm, then a chance of showers after 11pm. Mostly cloudy, with a low around 50. West wind 5 to 7 mph becoming calm. Chance of precipitation is 60%.

    Low: 50 °F

    Showers
    Likely

  • Friday

    Friday: A 40 percent chance of showers before 2pm. Partly sunny, with a high near 67.

    High: 67 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Partly cloudy, with a low around 53.

    Low: 53 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 71.

    High: 71 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 57.

    Low: 57 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly cloudy, with a low around 50. Southwest wind around 9 mph.
Wednesday
Mostly cloudy, with a high near 64. Breezy, with a south wind 11 to 16 mph increasing to 19 to 24 mph in the afternoon. Winds could gust as high as 37 mph.
Wednesday Night
Showers likely, mainly after 2am. Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 52. South wind 9 to 16 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday
Showers and possibly a thunderstorm. Patchy fog. High near 65. Southeast wind around 6 mph becoming calm in the morning. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm, then a chance of showers after 11pm. Mostly cloudy, with a low around 50. West wind 5 to 7 mph becoming calm. Chance of precipitation is 60%.
Friday
A 40 percent chance of showers before 2pm. Partly sunny, with a high near 67.
Friday Night
Partly cloudy, with a low around 53.
Saturday
Sunny, with a high near 71.
Saturday Night
Mostly clear, with a low around 57.
Sunday
Sunny, with a high near 78.
Sunday Night
Partly cloudy, with a low around 56.
Monday
Mostly sunny, with a high near 72.
Monday Night
Partly cloudy, with a low around 57.
Tuesday
Mostly sunny, with a high near 76.
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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:
2:36 pm EDT May 12, 2026
Forecast Valid:
12am EDT May 13, 2026-6pm EDT May 19, 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