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 Fog/Mist

59°F

15°C

Humidity 96%
Wind Speed E 16 G 23 mph
Barometer 30.15 in (1021.0 mb)
Dewpoint 58°F (14°C)
Visibility 4.00 mi
Last update 11 Oct 2:56 pm EDT
Extended Forecast for

Great River NY

  • This Afternoon

    This Afternoon: Rain. High near 64. East wind around 18 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 64 °F

    Rain

  • Tonight

    Tonight: Rain, mainly before 5am. Low around 56. Windy, with a northeast wind 17 to 26 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 56 °F

    Rain and
    Windy then
    Rain Likely

  • Columbus Day

    Columbus Day: A 30 percent chance of rain before 8am. Cloudy through mid morning, then gradual clearing, with a high near 70. Northeast wind 9 to 15 mph.

    High: 70 °F

    Chance Rain
    then Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 57. Northwest wind around 6 mph.

    Low: 57 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny through mid morning, then becoming mostly cloudy, with a high near 69. Light and variable wind becoming south 6 to 11 mph in the morning.

    High: 69 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 62.

    Low: 62 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 75.

    High: 75 °F

    Mostly Sunny

  • Wednesday Night

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

    Low: 56 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 64.

    High: 64 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Rain. High near 64. East wind around 18 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Tonight
Rain, mainly before 5am. Low around 56. Windy, with a northeast wind 17 to 26 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Columbus Day
A 30 percent chance of rain before 8am. Cloudy through mid morning, then gradual clearing, with a high near 70. Northeast wind 9 to 15 mph.
Monday Night
Mostly clear, with a low around 57. Northwest wind around 6 mph.
Tuesday
Sunny through mid morning, then becoming mostly cloudy, with a high near 69. Light and variable wind becoming south 6 to 11 mph in the morning.
Tuesday Night
Partly cloudy, with a low around 62.
Wednesday
Mostly sunny, with a high near 75.
Wednesday Night
Mostly cloudy, with a low around 56.
Thursday
Mostly sunny, with a high near 64.
Thursday Night
A 30 percent chance of showers after 2am. Partly cloudy, with a low around 53.
Friday
Showers likely. Mostly cloudy, with a high near 67. Breezy. Chance of precipitation is 60%.
Friday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 50. Windy.
Saturday
Partly sunny, with a high near 57. Windy.
Saturday Night
Mostly cloudy, with a low around 41. Windy.
Sunday
Mostly sunny, with a high near 54. Breezy.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Great River NY
 40.7°N 73.17°W (Elev. 7 ft)
Last Update:
2:29 pm EDT Oct 11, 2026
Forecast Valid:
3pm EDT Oct 11, 2026-6pm EDT Oct 18, 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