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.

Mostly Cloudy

35°F

2°C

Humidity 89%
Wind Speed SW 9 mph
Barometer 30.05 in (1017.6 mb)
Dewpoint 32°F (0°C)
Visibility 9.00 mi
Wind Chill28°F (-2°C)
Last update 17 Jan 4:56 pm EST
Extended Forecast for

Stony Brook NY

Winter Weather Advisory January 18, 10:00am until January 18, 10:00pm
Click here for hazard details and duration
Winter Weather Advisory

  • Tonight

    Tonight: A 40 percent chance of snow, mainly after 4am. Mostly cloudy, with a low around 31. West wind 5 to 8 mph becoming calm after midnight.

    Low: 31 °F

    Mostly Cloudy
    then Chance
    Snow

  • Sunday

    Sunday: Periods of snow, mainly after 7am. High near 34. Calm wind becoming northwest around 6 mph in the morning. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible.

    High: 34 °F

    Snow

  • Sunday Night

    Sunday Night: A 40 percent chance of snow before 1am. Cloudy, then gradually becoming partly cloudy, with a low around 24. Wind chill values between 15 and 20. North wind around 7 mph becoming northwest after midnight.

    Low: 24 °F

    Chance Snow

  • M.L.King Day

    M.L.King Day: Mostly sunny, with a high near 34. Wind chill values between 15 and 20. West wind 8 to 16 mph.

    High: 34 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 18. West wind 14 to 16 mph.

    Low: 18 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 25.

    High: 25 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 16.

    Low: 16 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 37.

    High: 37 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 30.

    Low: 30 °F

    Mostly Cloudy

Detailed Forecast

Tonight
A 40 percent chance of snow, mainly after 4am. Mostly cloudy, with a low around 31. West wind 5 to 8 mph becoming calm after midnight.
Sunday
Periods of snow, mainly after 7am. High near 34. Calm wind becoming northwest around 6 mph in the morning. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible.
Sunday Night
A 40 percent chance of snow before 1am. Cloudy, then gradually becoming partly cloudy, with a low around 24. Wind chill values between 15 and 20. North wind around 7 mph becoming northwest after midnight.
M.L.King Day
Mostly sunny, with a high near 34. Wind chill values between 15 and 20. West wind 8 to 16 mph.
Monday Night
Partly cloudy, with a low around 18. West wind 14 to 16 mph.
Tuesday
Mostly sunny, with a high near 25.
Tuesday Night
Mostly clear, with a low around 16.
Wednesday
Mostly sunny, with a high near 37.
Wednesday Night
Mostly cloudy, with a low around 30.
Thursday
Mostly cloudy, with a high near 38.
Thursday Night
Partly cloudy, with a low around 21.
Friday
Mostly sunny, with a high near 32.
Friday Night
Mostly cloudy, with a low around 24.
Saturday
Partly sunny, with a high near 33.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
5:41 pm EST Jan 17, 2026
Forecast Valid:
5pm EST Jan 17, 2026-6pm EST Jan 24, 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