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

46°F

8°C

Humidity 83%
Wind Speed SE 3 mph
Barometer 29.99 in (1015.5 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 11 Mar 2:56 am EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Overnight

    Overnight: Partly cloudy, with a low around 43. Calm wind.

    Low: 43 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers, mainly after 2pm. Areas of fog between 8am and 11am. Otherwise, increasing clouds, with a high near 64. South wind 5 to 10 mph.

    High: 64 °F

    Areas Fog
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms, mainly after 5am. Areas of fog before 3am. Otherwise, mostly cloudy, with a low around 42. South wind around 15 mph.

    Low: 42 °F

    Chance
    Showers and
    Areas Fog

  • Thursday

    Thursday: Rain showers likely before 2pm, then a slight chance of rain and snow showers. Cloudy, with a temperature rising to near 52 by 8am, then falling to around 41 during the remainder of the day. Northwest wind around 16 mph. Chance of precipitation is 60%. Little or no snow accumulation expected.

    High: 52 °F⇓

    Showers
    Likely then
    Chance
    Rain/Snow

  • Thursday Night

    Thursday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 33. Northwest wind 9 to 13 mph.

    Low: 33 °F

    Decreasing
    Clouds

  • Friday

    Friday: Increasing clouds, with a high near 46.

    High: 46 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 38.

    Low: 38 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 48.

    High: 48 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 32.

    Low: 32 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Partly cloudy, with a low around 43. Calm wind.
Wednesday
A 30 percent chance of showers, mainly after 2pm. Areas of fog between 8am and 11am. Otherwise, increasing clouds, with a high near 64. South wind 5 to 10 mph.
Wednesday Night
A 40 percent chance of showers and thunderstorms, mainly after 5am. Areas of fog before 3am. Otherwise, mostly cloudy, with a low around 42. South wind around 15 mph.
Thursday
Rain showers likely before 2pm, then a slight chance of rain and snow showers. Cloudy, with a temperature rising to near 52 by 8am, then falling to around 41 during the remainder of the day. Northwest wind around 16 mph. Chance of precipitation is 60%. Little or no snow accumulation expected.
Thursday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 33. Northwest wind 9 to 13 mph.
Friday
Increasing clouds, with a high near 46.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 38.
Saturday
Sunny, with a high near 48.
Saturday Night
Mostly cloudy, with a low around 32.
Sunday
Cloudy, with a high near 50.
Sunday Night
Rain. Low around 42. Chance of precipitation is 80%.
Monday
Rain. High near 55. Breezy. Chance of precipitation is 90%.
Monday Night
Rain likely. Mostly cloudy, with a low around 30. Chance of precipitation is 60%.
Tuesday
Mostly sunny, with a high near 40.
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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:
3:05 am EDT Mar 11, 2026
Forecast Valid:
3am EDT Mar 11, 2026-6pm EDT Mar 17, 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