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

73°F

23°C

Humidity 46%
Wind Speed NW 20 G 30 mph
Barometer 29.73 in (1006.7 mb)
Dewpoint 51°F (11°C)
Visibility 10.00 mi
Last update 20 Jun 9:56 am EDT
Extended Forecast for

Great River NY

  • Today

    Today: Sunny, with a high near 80. West wind around 17 mph, with gusts as high as 28 mph.

    High: 80 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 64. West wind 5 to 8 mph becoming calm in the evening.

    Low: 64 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 79. Light and variable wind becoming southwest 5 to 10 mph in the morning.

    High: 79 °F

    Sunny

  • Sunday Night

    Sunday Night: A 20 percent chance of showers after 2am. Partly cloudy, with a low around 64. Southwest wind around 5 mph becoming calm in the evening.

    Low: 64 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Monday

    Monday: Showers likely, then showers and possibly a thunderstorm after 2pm. High near 75. Light southeast wind becoming south 11 to 16 mph in the morning. Winds could gust as high as 30 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.

    High: 75 °F

    Showers

  • Monday Night

    Monday Night: Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 65 °F

    Showers

  • Tuesday

    Tuesday: A 30 percent chance of showers before 8am. Mostly sunny, with a high near 78.

    High: 78 °F

    Chance
    Showers then
    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

Detailed Forecast

Today
Sunny, with a high near 80. West wind around 17 mph, with gusts as high as 28 mph.
Tonight
Mostly clear, with a low around 64. West wind 5 to 8 mph becoming calm in the evening.
Sunday
Sunny, with a high near 79. Light and variable wind becoming southwest 5 to 10 mph in the morning.
Sunday Night
A 20 percent chance of showers after 2am. Partly cloudy, with a low around 64. Southwest wind around 5 mph becoming calm in the evening.
Monday
Showers likely, then showers and possibly a thunderstorm after 2pm. High near 75. Light southeast wind becoming south 11 to 16 mph in the morning. Winds could gust as high as 30 mph. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Monday Night
Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Tuesday
A 30 percent chance of showers before 8am. Mostly sunny, with a high near 78.
Tuesday Night
Mostly clear, with a low around 65.
Wednesday
Sunny, with a high near 79.
Wednesday Night
Mostly clear, with a low around 65.
Thursday
Sunny, with a high near 78.
Thursday Night
Partly cloudy, with a low around 66.
Friday
A 30 percent chance of showers. Partly sunny, with a high near 79.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Great River NY
 40.72°N 73.16°W (Elev. 13 ft)
Last Update:
2:19 am EDT Jun 20, 2026
Forecast Valid:
11am EDT Jun 20, 2026-6pm EDT Jun 26, 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