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

69°F

21°C

Humidity 31%
Wind Speed NW 10 mph
Barometer 30.17 in (1021.7 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Last update 4 Apr 4:56 pm EDT
Extended Forecast for

Stony Brook NY

  • Tonight

    Tonight: Mostly cloudy, with a low around 44. North wind 5 to 7 mph becoming northeast after midnight.

    Low: 44 °F

    Mostly Cloudy

  • Saturday

    Saturday: Rain likely, mainly after 11am. Cloudy, with a steady temperature around 47. Southeast wind 10 to 15 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 47 °F

    Rain Likely

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms, mainly between 2am and 5am. Cloudy, with a steady temperature around 47. East wind 5 to 9 mph becoming light southeast after midnight. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 47 °F

    Showers
    Likely

  • Sunday

    Sunday: Showers likely, mainly after 8am. Mostly cloudy, with a high near 57. Southwest wind 6 to 9 mph becoming northwest in the afternoon. Chance of precipitation is 60%.

    High: 57 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: Showers. Low around 39. North wind around 6 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 39 °F

    Showers

  • Monday

    Monday: Showers, mainly before 8am. High near 49. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 49 °F

    Showers then
    Chance
    Showers

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 36.

    Low: 36 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 48.

    High: 48 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 30.

    Low: 30 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 44. North wind 5 to 7 mph becoming northeast after midnight.
Saturday
Rain likely, mainly after 11am. Cloudy, with a steady temperature around 47. Southeast wind 10 to 15 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday Night
Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms, mainly between 2am and 5am. Cloudy, with a steady temperature around 47. East wind 5 to 9 mph becoming light southeast after midnight. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
Showers likely, mainly after 8am. Mostly cloudy, with a high near 57. Southwest wind 6 to 9 mph becoming northwest in the afternoon. Chance of precipitation is 60%.
Sunday Night
Showers. Low around 39. North wind around 6 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday
Showers, mainly before 8am. High near 49. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Monday Night
Mostly cloudy, with a low around 36.
Tuesday
Mostly sunny, with a high near 48.
Tuesday Night
Mostly clear, with a low around 30.
Wednesday
Sunny, with a high near 50.
Wednesday Night
Mostly clear, with a low around 36.
Thursday
Mostly sunny, with a high near 54.
Thursday Night
Mostly cloudy, with a low around 42.
Friday
A 30 percent chance of showers. Partly sunny, with a high near 58.
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ABOUT THIS FORECAST

 
Point Forecast:
Stony Brook NY
 40.92°N 73.12°W (Elev. 112 ft)
Last Update:
3:20 pm EDT Apr 4, 2025
Forecast Valid:
5pm EDT Apr 4, 2025-6pm EDT Apr 11, 2025
 
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