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.

A Few Clouds

69°F

21°C

Humidity 66%
Wind Speed SW 6 mph
Barometer 30.18 in (1021.9 mb)
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Last update 29 Aug 7:56 pm EDT
Extended Forecast for

Port Jefferson Station NY

  • Tonight

    Tonight: Mostly clear, with a low around 63. Southwest wind 3 to 6 mph.

    Low: 63 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 80. Southwest wind 6 to 11 mph.

    High: 80 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Showers and thunderstorms likely before 2am, then a chance of showers. Mostly cloudy, with a low around 67. Southwest wind 5 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 67 °F

    Showers
    Likely

  • Monday

    Monday: Cloudy, then gradually becoming mostly sunny, with a high near 79. Northeast wind 3 to 5 mph.

    High: 79 °F

    Decreasing
    Clouds

  • Monday Night

    Monday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 66. South wind 3 to 5 mph.

    Low: 66 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 79.

    High: 79 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 60%.

    Low: 68 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A chance of showers before 8am, then a chance of showers after 2pm. Mostly cloudy, with a high near 80. Chance of precipitation is 30%.

    High: 80 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 68.

    Low: 68 °F

    Chance
    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 63. Southwest wind 3 to 6 mph.
Sunday
Mostly sunny, with a high near 80. Southwest wind 6 to 11 mph.
Sunday Night
Showers and thunderstorms likely before 2am, then a chance of showers. Mostly cloudy, with a low around 67. Southwest wind 5 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday
Cloudy, then gradually becoming mostly sunny, with a high near 79. Northeast wind 3 to 5 mph.
Monday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 66. South wind 3 to 5 mph.
Tuesday
A 50 percent chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 79.
Tuesday Night
A chance of showers and thunderstorms before 8pm, then showers likely and possibly a thunderstorm between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 60%.
Wednesday
A chance of showers before 8am, then a chance of showers after 2pm. Mostly cloudy, with a high near 80. Chance of precipitation is 30%.
Wednesday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 68.
Thursday
A 40 percent chance of showers. Mostly cloudy, with a high near 81.
Thursday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 66.
Friday
Mostly sunny, with a high near 78.
Friday Night
A 30 percent chance of showers. Partly cloudy, with a low around 63.
Saturday
Mostly sunny, with a high near 75.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson Station NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
2:24 pm EDT Aug 29, 2026
Forecast Valid:
8pm EDT Aug 29, 2026-6pm EDT Sep 5, 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