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.

A Few Clouds

31°F

-1°C

Humidity 76%
Wind Speed E 3 mph
Barometer 30.16 in (1021.4 mb)
Dewpoint 24°F (-4°C)
Visibility 10.00 mi
Last update 27 Feb 6:56 pm EST
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Tonight

    Tonight: Patchy fog between 3am and 5am. Otherwise, mostly clear, with a low around 29. Calm wind.

    Low: 29 °F

    Mostly Clear
    then Patchy
    Fog

  • Saturday

    Saturday: Patchy fog before 8am. Otherwise, mostly sunny, with a high near 45. Calm wind becoming southwest around 6 mph.

    High: 45 °F

    Patchy Fog
    then Mostly
    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 29. Light and variable wind.

    Low: 29 °F

    Partly Cloudy

  • Sunday

    Sunday: Snow showers likely before 4pm, then a slight chance of rain and snow showers. Cloudy, then becoming mostly sunny during the afternoon, with a high near 39. Northwest wind 5 to 10 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.

    High: 39 °F

    Snow Showers
    Likely then
    Rain/Snow
    Likely

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 18. North wind around 11 mph.

    Low: 18 °F

    Mostly Clear

  • Monday

    Monday: Partly sunny, with a high near 29.

    High: 29 °F

    Partly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 21.

    Low: 21 °F

    Partly Cloudy

  • Tuesday

    Tuesday: A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 41. Chance of precipitation is 50%.

    High: 41 °F

    Chance
    Rain/Snow

  • Tuesday Night

    Tuesday Night: Rain likely. Cloudy, with a low around 35. Chance of precipitation is 70%.

    Low: 35 °F

    Rain Likely

Detailed Forecast

Tonight
Patchy fog between 3am and 5am. Otherwise, mostly clear, with a low around 29. Calm wind.
Saturday
Patchy fog before 8am. Otherwise, mostly sunny, with a high near 45. Calm wind becoming southwest around 6 mph.
Saturday Night
Partly cloudy, with a low around 29. Light and variable wind.
Sunday
Snow showers likely before 4pm, then a slight chance of rain and snow showers. Cloudy, then becoming mostly sunny during the afternoon, with a high near 39. Northwest wind 5 to 10 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Sunday Night
Mostly clear, with a low around 18. North wind around 11 mph.
Monday
Partly sunny, with a high near 29.
Monday Night
Partly cloudy, with a low around 21.
Tuesday
A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 41. Chance of precipitation is 50%.
Tuesday Night
Rain likely. Cloudy, with a low around 35. Chance of precipitation is 70%.
Wednesday
A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 45.
Wednesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 34.
Thursday
A 40 percent chance of rain. Cloudy, with a high near 45.
Thursday Night
Rain likely. Cloudy, with a low around 35. Chance of precipitation is 60%.
Friday
A 40 percent chance of rain. Cloudy, with a high near 42.
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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:
5:52 pm EST Feb 27, 2026
Forecast Valid:
7pm EST Feb 27, 2026-6pm EST Mar 6, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation