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

66°F

19°C

Humidity 63%
Wind Speed SW 9 mph
Barometer 30.01 in (1016.0 mb)
Dewpoint 53°F (12°C)
Visibility 10.00 mi
Last update 1 Apr 9:56 am EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Today

    Today: A chance of showers, then showers and possibly a thunderstorm after 2pm. High near 70. West wind 8 to 11 mph. Chance of precipitation is 80%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 70 °F

    Chance
    Showers then
    Showers

  • Tonight

    Tonight: Showers, mainly before 5am. Patchy fog after 2am. Low around 41. East wind 6 to 14 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 41 °F

    Showers and
    Patchy Fog

  • Thursday

    Thursday: A 40 percent chance of rain, mainly before 2pm. Patchy fog before 2pm. Otherwise, cloudy, with a high near 46. East wind around 15 mph.

    High: 46 °F

    Chance Rain
    and Patchy
    Fog

  • Thursday Night

    Thursday Night: A slight chance of rain or drizzle before 8pm, then a chance of drizzle or light rain, mainly after 2am. Areas of fog after 8pm. Otherwise, cloudy, with a low around 40. East wind 7 to 13 mph. Chance of precipitation is 30%.

    Low: 40 °F

    Chance Light
    Rain and
    Areas Fog

  • Friday

    Friday: A chance of drizzle or light rain, mainly before 8am. Areas of fog before 11am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 59. Light and variable wind becoming southwest 5 to 8 mph in the afternoon. Chance of precipitation is 30%.

    High: 59 °F

    Chance Light
    Rain and
    Areas Fog
    then Mostly
    Cloudy

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 51.

    Low: 51 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of showers after 8pm. Mostly cloudy, with a low around 48.

    Low: 48 °F

    Chance
    Showers

  • Sunday

    Sunday: Showers likely. Mostly cloudy, with a high near 60. Chance of precipitation is 70%.

    High: 60 °F

    Showers
    Likely

Detailed Forecast

Today
A chance of showers, then showers and possibly a thunderstorm after 2pm. High near 70. West wind 8 to 11 mph. Chance of precipitation is 80%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
Showers, mainly before 5am. Patchy fog after 2am. Low around 41. East wind 6 to 14 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Thursday
A 40 percent chance of rain, mainly before 2pm. Patchy fog before 2pm. Otherwise, cloudy, with a high near 46. East wind around 15 mph.
Thursday Night
A slight chance of rain or drizzle before 8pm, then a chance of drizzle or light rain, mainly after 2am. Areas of fog after 8pm. Otherwise, cloudy, with a low around 40. East wind 7 to 13 mph. Chance of precipitation is 30%.
Friday
A chance of drizzle or light rain, mainly before 8am. Areas of fog before 11am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 59. Light and variable wind becoming southwest 5 to 8 mph in the afternoon. Chance of precipitation is 30%.
Friday Night
Mostly cloudy, with a low around 51.
Saturday
Mostly sunny, with a high near 65.
Saturday Night
A 30 percent chance of showers after 8pm. Mostly cloudy, with a low around 48.
Sunday
Showers likely. Mostly cloudy, with a high near 60. Chance of precipitation is 70%.
Sunday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 40.
Monday
Mostly sunny, with a high near 53.
Monday Night
Mostly clear, with a low around 38.
Tuesday
Mostly sunny, with a high near 51.
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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:
5:58 am EDT Apr 1, 2026
Forecast Valid:
10am EDT Apr 1, 2026-6pm EDT Apr 7, 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