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

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fog/Mist

66°F

19°C

Humidity 96%
Wind Speed S 5 mph
Barometer 29.98 in (1015.3 mb)
Dewpoint 65°F (18°C)
Visibility 0.75 mi
Last update 18 Jun 1:56 am EDT
Extended Forecast for

Port Jefferson NYSimilar City Names

Dense Fog Advisory until June 18, 07:00am
Click here for hazard details and duration
Dense Fog Advisory
  •  
    Dense Fog Advisory until June 18, 07:00am

    NOW until 7:00am Wed

    Dense Fog Advisory

  • Overnight

    Low: 65 °F

    Chance
    Showers and
    Areas Dense
    Fog

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly after 2pm. Areas of dense fog before 8am. Otherwise, cloudy, with a high near 77. South wind 5 to 7 mph.

    High: 77 °F

    Chance
    Showers and
    Areas Dense
    Fog then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 68. South wind around 6 mph.

    Low: 68 °F

    Chance
    T-storms

  • Juneteenth

    Juneteenth: A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Southwest wind 7 to 14 mph.

    High: 88 °F

    Mostly Sunny
    then Chance
    T-storms

  • Thursday Night

    Thursday Night: A 30 percent chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 66. Southwest wind 11 to 14 mph.

    Low: 66 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 83.

    High: 83 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

Detailed Forecast

Overnight
A 40 percent chance of showers and thunderstorms. Areas of dense fog. Otherwise, cloudy, with a low around 65. Southeast wind around 5 mph.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly after 2pm. Areas of dense fog before 8am. Otherwise, cloudy, with a high near 77. South wind 5 to 7 mph.
Wednesday Night
A 30 percent chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 68. South wind around 6 mph.
Juneteenth
A 30 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Southwest wind 7 to 14 mph.
Thursday Night
A 30 percent chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 66. Southwest wind 11 to 14 mph.
Friday
Sunny, with a high near 83.
Friday Night
Mostly clear, with a low around 65.
Saturday
Mostly sunny, with a high near 84.
Saturday Night
Mostly cloudy, with a low around 69.
Sunday
Mostly sunny, with a high near 87.
Sunday Night
Mostly clear, with a low around 71.
Monday
Sunny, with a high near 90.
Monday Night
Mostly clear, with a low around 73.
Tuesday
Sunny, with a high near 91.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NYSimilar City Names
 40.95°N 73.05°W (Elev. 151 ft)
Last Update:
9:55 pm EDT Jun 17, 2025
Forecast Valid:
2am EDT Jun 18, 2025-6pm EDT Jun 24, 2025
 
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Additional Resources

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Chance of Precipitation