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.

Overcast

63°F

17°C

Humidity 65%
Wind Speed E 10 mph
Barometer 30.24 in (1024.1 mb)
Dewpoint 51°F (11°C)
Visibility 10.00 mi
Last update 4 Oct 11:56 am EDT
Extended Forecast for

North Great River NY

  • This Afternoon

    This Afternoon: Showers, mainly after 2pm. High near 64. East wind 10 to 13 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 64 °F

    Showers

  • Tonight

    Tonight: Showers, mainly before 8pm. Low around 55. Northeast wind 5 to 8 mph becoming light and variable after midnight. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 55 °F

    Showers then
    Mostly Cloudy

  • Monday

    Monday: Partly sunny, then gradually becoming sunny, with a high near 68. West wind 6 to 11 mph increasing to 13 to 18 mph in the afternoon.

    High: 68 °F

    Becoming
    Sunny

  • Monday Night

    Monday Night: Clear, with a low around 47. Northwest wind 10 to 14 mph.

    Low: 47 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 62. Northwest wind around 10 mph.

    High: 62 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Clear, with a low around 50.

    Low: 50 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 65.

    High: 65 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 56.

    Low: 56 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 69.

    High: 69 °F

    Sunny

Detailed Forecast

This Afternoon
Showers, mainly after 2pm. High near 64. East wind 10 to 13 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
Showers, mainly before 8pm. Low around 55. Northeast wind 5 to 8 mph becoming light and variable after midnight. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Monday
Partly sunny, then gradually becoming sunny, with a high near 68. West wind 6 to 11 mph increasing to 13 to 18 mph in the afternoon.
Monday Night
Clear, with a low around 47. Northwest wind 10 to 14 mph.
Tuesday
Sunny, with a high near 62. Northwest wind around 10 mph.
Tuesday Night
Clear, with a low around 50.
Wednesday
Sunny, with a high near 65.
Wednesday Night
Mostly clear, with a low around 56.
Thursday
Sunny, with a high near 69.
Thursday Night
Mostly clear, with a low around 56.
Friday
Sunny, with a high near 68.
Friday Night
Partly cloudy, with a low around 55.
Saturday
Mostly sunny, with a high near 65.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
North Great River NY
 40.74°N 73.16°W (Elev. 7 ft)
Last Update:
10:11 am EDT Oct 4, 2026
Forecast Valid:
12pm EDT Oct 4, 2026-6pm EDT Oct 10, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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