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

40°F

4°C

Humidity 79%
Wind Speed S 9 mph
Barometer 29.82 in (1009.7 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Wind Chill34°F (1°C)
Last update 13 Mar 11:56 pm EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Overnight

    Overnight: A 20 percent chance of showers before 2am. Mostly clear, with a low around 39. Breezy, with a southwest wind 16 to 21 mph.

    Low: 39 °F

    Slight Chance
    Showers and
    Breezy

  • Saturday

    Saturday: Sunny, with a high near 48. Breezy, with a west wind around 22 mph, with gusts as high as 38 mph.

    High: 48 °F

    Sunny and
    Breezy

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 34. West wind 5 to 15 mph.

    Low: 34 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Mostly cloudy, with a high near 48. Northeast wind 5 to 10 mph becoming southeast in the afternoon.

    High: 48 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Rain after 2am. Low around 40. Southeast wind 11 to 17 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 40 °F

    Mostly Cloudy
    then Rain

  • Monday

    Monday: Rain, with thunderstorms also possible after 2pm. High near 58. Breezy. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 58 °F

    Rain and
    Breezy

  • Monday Night

    Monday Night: Rain and possibly a thunderstorm. Low around 37. Windy. Chance of precipitation is 100%.

    Low: 37 °F

    Rain and
    Windy

  • Tuesday

    Tuesday: A 30 percent chance of rain before 8am. Mostly sunny, with a high near 45. Breezy.

    High: 45 °F

    Breezy.
    Chance Rain
    then Mostly
    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 26.

    Low: 26 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 20 percent chance of showers before 2am. Mostly clear, with a low around 39. Breezy, with a southwest wind 16 to 21 mph.
Saturday
Sunny, with a high near 48. Breezy, with a west wind around 22 mph, with gusts as high as 38 mph.
Saturday Night
Increasing clouds, with a low around 34. West wind 5 to 15 mph.
Sunday
Mostly cloudy, with a high near 48. Northeast wind 5 to 10 mph becoming southeast in the afternoon.
Sunday Night
Rain after 2am. Low around 40. Southeast wind 11 to 17 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday
Rain, with thunderstorms also possible after 2pm. High near 58. Breezy. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Monday Night
Rain and possibly a thunderstorm. Low around 37. Windy. Chance of precipitation is 100%.
Tuesday
A 30 percent chance of rain before 8am. Mostly sunny, with a high near 45. Breezy.
Tuesday Night
Partly cloudy, with a low around 26.
Wednesday
Mostly sunny, with a high near 39.
Wednesday Night
Mostly cloudy, with a low around 31.
Thursday
Partly sunny, with a high near 44.
Thursday Night
Partly cloudy, with a low around 35.
Friday
Partly sunny, with a high near 47.
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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:
9:14 pm EDT Mar 13, 2026
Forecast Valid:
12am EDT Mar 14, 2026-6pm EDT Mar 20, 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