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

38°F

3°C

Humidity 60%
Wind Speed Calm
Barometer 29.87 in (1011.5 mb)
Dewpoint 25°F (-4°C)
Visibility 10.00 mi
Last update 26 Feb 5:56 pm EST
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Tonight

    Tonight: A 20 percent chance of snow showers before 7pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 25. Calm wind becoming northeast around 5 mph.

    Low: 25 °F

    Slight Chance
    Snow Showers
    then Mostly
    Clear

  • Friday

    Friday: Sunny, with a high near 39. Calm wind becoming south around 5 mph.

    High: 39 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 31. Light south wind.

    Low: 31 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 45. South wind around 6 mph.

    High: 45 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 30. Light and variable wind becoming north around 6 mph after midnight.

    Low: 30 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 37.

    High: 37 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 19.

    Low: 19 °F

    Partly Cloudy

  • Monday

    Monday: A 30 percent chance of snow after 1pm. Partly sunny, with a high near 29.

    High: 29 °F

    Mostly Sunny
    then Chance
    Snow

  • Monday Night

    Monday Night: Partly cloudy, with a low around 22.

    Low: 22 °F

    Partly Cloudy

Detailed Forecast

Tonight
A 20 percent chance of snow showers before 7pm. Mostly cloudy, then gradually becoming mostly clear, with a low around 25. Calm wind becoming northeast around 5 mph.
Friday
Sunny, with a high near 39. Calm wind becoming south around 5 mph.
Friday Night
Mostly clear, with a low around 31. Light south wind.
Saturday
Mostly sunny, with a high near 45. South wind around 6 mph.
Saturday Night
Partly cloudy, with a low around 30. Light and variable wind becoming north around 6 mph after midnight.
Sunday
Partly sunny, with a high near 37.
Sunday Night
Partly cloudy, with a low around 19.
Monday
A 30 percent chance of snow after 1pm. Partly sunny, with a high near 29.
Monday Night
Partly cloudy, with a low around 22.
Tuesday
Partly sunny, with a high near 36.
Tuesday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 30.
Wednesday
A 40 percent chance of rain. Partly sunny, with a high near 43.
Wednesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 31.
Thursday
A 30 percent chance of rain. Mostly cloudy, with a high near 44.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
12:59 pm EST Feb 26, 2026
Forecast Valid:
6pm EST Feb 26, 2026-6pm EST Mar 5, 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