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.

Mostly Cloudy

76°F

24°C

Humidity 54%
Wind Speed S 9 mph
Barometer 29.87 in (1011.3 mb)
Dewpoint 58°F (14°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 15 Apr 3:56 pm EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 78. South wind around 10 mph.

    High: 78 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 57. South wind 5 to 9 mph. Chance of precipitation is 40%.

    Low: 57 °F

    Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: Mostly sunny, with a high near 79. Southwest wind 5 to 10 mph.

    High: 79 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 58. South wind 5 to 10 mph.

    Low: 58 °F

    Mostly Cloudy

  • Friday

    Friday: A 40 percent chance of showers, mainly after 2pm. Partly sunny, with a high near 73. West wind around 7 mph.

    High: 73 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 51.

    Low: 51 °F

    Chance
    Showers then
    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 61.

    High: 61 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 48.

    Low: 48 °F

    Mostly Cloudy
    then Chance
    Showers

  • Sunday

    Sunday: Showers likely, mainly after 8am. Cloudy, with a high near 59. Chance of precipitation is 70%.

    High: 59 °F

    Showers
    Likely

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 78. South wind around 10 mph.
Tonight
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 57. South wind 5 to 9 mph. Chance of precipitation is 40%.
Thursday
Mostly sunny, with a high near 79. Southwest wind 5 to 10 mph.
Thursday Night
Mostly cloudy, with a low around 58. South wind 5 to 10 mph.
Friday
A 40 percent chance of showers, mainly after 2pm. Partly sunny, with a high near 73. West wind around 7 mph.
Friday Night
A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 51.
Saturday
Partly sunny, with a high near 61.
Saturday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 48.
Sunday
Showers likely, mainly after 8am. Cloudy, with a high near 59. Chance of precipitation is 70%.
Sunday Night
A 30 percent chance of showers before 2am. Mostly cloudy, with a low around 38.
Monday
Mostly sunny, with a high near 51.
Monday Night
Mostly clear, with a low around 35.
Tuesday
Sunny, with a high near 54.
Tuesday Night
Partly cloudy, with a low around 45.
Wednesday
Partly sunny, with a high near 63.
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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:
2:22 pm EDT Apr 15, 2026
Forecast Valid:
4pm EDT Apr 15, 2026-6pm EDT Apr 22, 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