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

33°F

1°C

Humidity 66%
Wind Speed NE 5 mph
Barometer 30.40 in (1029.5 mb)
Dewpoint 23°F (-5°C)
Visibility 10.00 mi
Wind Chill28°F (-2°C)
Last update 15 Mar 4:56 am EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Today

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

    High: 48 °F

    Mostly Cloudy

  • Tonight

    Tonight: Showers, with thunderstorms also possible after 5am. Patchy fog after 2am. Temperature falling to near 40 by 8pm, then rising to around 48 during the remainder of the night. Southeast wind 10 to 16 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 40 °F⇑

    Slight Chance
    Showers then
    Showers and
    Patchy Fog

  • Monday

    Monday: Intermittent showers and thunderstorms. Patchy fog before noon. Otherwise, cloudy, with a high near 58. Breezy, with a south wind 21 to 24 mph, with gusts as high as 40 mph. Chance of precipitation is 50%.

    High: 58 °F

    Intermittent
    T-storms and
    Patchy Fog

  • Monday Night

    Monday Night: Periods of showers and possibly a thunderstorm before 2am, then a chance of showers. Some of the storms could produce heavy rainfall. Low around 35. Windy, with a south wind 25 to 32 mph becoming west after midnight. Winds could gust as high as 46 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 35 °F

    Heavy Rain
    and Windy

  • Tuesday

    Tuesday: A 30 percent chance of showers before 8am. Mostly sunny, with a steady temperature around 38. West wind around 18 mph, with gusts as high as 28 mph.

    High: 38 °F

    Chance
    Showers then
    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 25.

    Low: 25 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Increasing clouds, with a high near 38.

    High: 38 °F

    Increasing
    Clouds

  • Wednesday Night

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

    Low: 30 °F

    Mostly Cloudy

  • Thursday

    Thursday: Partly sunny, with a high near 45.

    High: 45 °F

    Partly Sunny

Detailed Forecast

Today
Mostly cloudy, with a high near 48. Northeast wind 5 to 10 mph becoming southeast in the afternoon.
Tonight
Showers, with thunderstorms also possible after 5am. Patchy fog after 2am. Temperature falling to near 40 by 8pm, then rising to around 48 during the remainder of the night. Southeast wind 10 to 16 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Monday
Intermittent showers and thunderstorms. Patchy fog before noon. Otherwise, cloudy, with a high near 58. Breezy, with a south wind 21 to 24 mph, with gusts as high as 40 mph. Chance of precipitation is 50%.
Monday Night
Periods of showers and possibly a thunderstorm before 2am, then a chance of showers. Some of the storms could produce heavy rainfall. Low around 35. Windy, with a south wind 25 to 32 mph becoming west after midnight. Winds could gust as high as 46 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday
A 30 percent chance of showers before 8am. Mostly sunny, with a steady temperature around 38. West wind around 18 mph, with gusts as high as 28 mph.
Tuesday Night
Partly cloudy, with a low around 25.
Wednesday
Increasing clouds, with a high near 38.
Wednesday Night
Mostly cloudy, with a low around 30.
Thursday
Partly sunny, with a high near 45.
Thursday Night
Mostly cloudy, with a low around 34.
Friday
Mostly sunny, with a high near 49.
Friday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 36.
Saturday
A 50 percent chance of rain. Partly sunny, with a high near 49.
Basemap Options
Click map to change the forecast location
Loading map...
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:
4:56 am EDT Mar 15, 2026
Forecast Valid:
5am EDT Mar 15, 2026-6pm EDT Mar 21, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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