Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Partly Cloudy

77°F

25°C

Humidity 90%
Wind Speed SW 5 mph
Barometer 29.94 in (1013.6 mb)
Dewpoint 74°F (23°C)
Visibility 8.00 mi
Heat Index78°F (26°C)
Last update 8 Jul 4:56 am EDT
Extended Forecast for

Port Jefferson NY

Flood Watch July 8, 02:00pm until July 9, 02:00am
Heat Advisory July 8, 10:00am until July 8, 08:00pm
Click here for hazard details and duration
Flood Watch
Heat Advisory
  • Today

    Today: A 30 percent chance of showers and thunderstorms after 2pm.  Patchy fog before 10am.  Otherwise, mostly sunny, with a high near 92. Heat index values as high as 98. West wind 5 to 8 mph.

    High: 92 °F

    Patchy Fog
    then Chance
    T-storms

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Some of the storms could produce heavy rainfall.  Mostly cloudy, with a low around 73. Southwest wind around 6 mph.  Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 73 °F

    Heavy Rain

  • Wednesday

    Wednesday: A slight chance of showers, then a chance of showers and thunderstorms after 2pm.  Partly sunny, with a high near 86. West wind 3 to 6 mph.  Chance of precipitation is 30%.

    High: 86 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms.  Mostly cloudy, with a low around 72. South wind around 6 mph.  Chance of precipitation is 50%.

    Low: 72 °F

    Chance
    T-storms

  • Thursday

    Thursday: A chance of showers before 11am, then a chance of showers and thunderstorms between 11am and 2pm, then showers likely and possibly a thunderstorm after 2pm.  Mostly cloudy, with a high near 82. Southeast wind 5 to 7 mph.  Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am.  Cloudy, with a low around 70. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 70 °F

    Showers
    Likely

  • Friday

    Friday: Mostly cloudy, with a high near 82.

    High: 82 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 70.

    Low: 70 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 84.

    High: 84 °F

    Partly Sunny

Detailed Forecast

Today
A 30 percent chance of showers and thunderstorms after 2pm. Patchy fog before 10am. Otherwise, mostly sunny, with a high near 92. Heat index values as high as 98. West wind 5 to 8 mph.
Tonight
Showers likely and possibly a thunderstorm before 2am, then a chance of showers and thunderstorms after 2am. Some of the storms could produce heavy rainfall. Mostly cloudy, with a low around 73. Southwest wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
A slight chance of showers, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 86. West wind 3 to 6 mph. Chance of precipitation is 30%.
Wednesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 72. South wind around 6 mph. Chance of precipitation is 50%.
Thursday
A chance of showers before 11am, then a chance of showers and thunderstorms between 11am and 2pm, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 82. Southeast wind 5 to 7 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Cloudy, with a low around 70. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Friday
Mostly cloudy, with a high near 82.
Friday Night
Mostly cloudy, with a low around 70.
Saturday
Partly sunny, with a high near 84.
Saturday Night
Mostly cloudy, with a low around 71.
Sunday
Partly sunny, with a high near 84.
Sunday Night
Mostly cloudy, with a low around 71.
Monday
A 30 percent chance of showers. Partly sunny, with a high near 84.
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.95°N 73.05°W (Elev. 151 ft)
4:54 am EDT Jul 8, 2025
5am EDT Jul 8, 2025-6pm EDT Jul 14, 2025
 
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Additional Resources

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