National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Heavy Rains Expected to Impact Parts of the Eastern U.S.

A strong cold front will produce heavy rain will create mainly localized areas of flash flooding to the Great Lakes and Ohio Valley. There is another flash flood threat in the parts of the Southeast and Southern Appalachians. Read More >

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

57°F

14°C

Humidity 87%
Wind Speed Calm
Barometer 30.35 in (1027.8 mb)
Dewpoint 53°F (12°C)
Visibility 10.00 mi
Last update 21 Sep 6:56 am EDT
Extended Forecast for

Stony Brook NY

  • Today

    Today: A 20 percent chance of showers after 2pm. Partly sunny, with a high near 75. Southeast wind 6 to 8 mph.

    Partly Sunny
    then Slight
    Chance
    Showers

    High: 75 °F

  • Tonight

    Tonight: A 20 percent chance of showers. Mostly cloudy, with a low around 67. Southeast wind around 7 mph.

    Slight Chance
    Showers

    Low: 67 °F

  • Wednesday

    Wednesday: A 30 percent chance of showers, mainly before 2pm. Mostly cloudy, with a high near 78. South wind 8 to 14 mph.

    Chance
    Showers

    High: 78 °F

  • Wednesday
    Night

    Wednesday Night: A 30 percent chance of showers, mainly after 2am. Mostly cloudy, with a low around 69. Southeast wind 10 to 13 mph.

    Chance
    Showers

    Low: 69 °F

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 11am. Partly sunny, with a high near 77. Southeast wind around 14 mph. Chance of precipitation is 50%.

    Chance
    Showers

    High: 77 °F

  • Thursday
    Night

    Thursday Night: Showers likely, mainly after 2am. Mostly cloudy, with a low around 65. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Showers
    Likely

    Low: 65 °F

  • Friday

    Friday: Showers likely, mainly before 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 74. Chance of precipitation is 60%.

    Showers
    Likely

    High: 74 °F

  • Friday
    Night

    Friday Night: A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 61.

    Chance
    Showers then
    Partly Cloudy

    Low: 61 °F

  • Saturday

    Saturday: Mostly sunny, with a high near 74.

    Mostly Sunny

    High: 74 °F

Detailed Forecast

Today
A 20 percent chance of showers after 2pm. Partly sunny, with a high near 75. Southeast wind 6 to 8 mph.
Tonight
A 20 percent chance of showers. Mostly cloudy, with a low around 67. Southeast wind around 7 mph.
Wednesday
A 30 percent chance of showers, mainly before 2pm. Mostly cloudy, with a high near 78. South wind 8 to 14 mph.
Wednesday Night
A 30 percent chance of showers, mainly after 2am. Mostly cloudy, with a low around 69. Southeast wind 10 to 13 mph.
Thursday
A chance of showers, with thunderstorms also possible after 11am. Partly sunny, with a high near 77. Southeast wind around 14 mph. Chance of precipitation is 50%.
Thursday Night
Showers likely, mainly after 2am. Mostly cloudy, with a low around 65. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday
Showers likely, mainly before 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 74. Chance of precipitation is 60%.
Friday Night
A 30 percent chance of showers before 8pm. Partly cloudy, with a low around 61.
Saturday
Mostly sunny, with a high near 74.
Saturday Night
Partly cloudy, with a low around 61.
Sunday
Mostly sunny, with a high near 74.
Sunday Night
Mostly clear, with a low around 59.
Monday
Sunny, with a high near 72.
Click Map For Forecast
Disclaimer
Map Legend
Point Forecast:
Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
6:15 am EDT Sep 21, 2021
Forecast Valid:
7am EDT Sep 21, 2021-6pm EDT Sep 27, 2021
 
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