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

43°F

6°C

Humidity 97%
Wind Speed SW 9 mph
Barometer 29.77 in (1008.0 mb)
Dewpoint 42°F (6°C)
Visibility 0.50 mi
Wind Chill38°F (3°C)
Last update 8 Mar 4:56 am EDT
Extended Forecast for

Port Jefferson NY

Dense Fog Advisory March 8, 06:03am until March 8, 09:00am
Click here for hazard details and duration
...
  •  
    Dense Fog Advisory March 8, 06:03am until March 8, 09:00am

    NOW until 9:00am Sun

    Dense Fog Advisory

  • Today

    High: 59 °F

    Chance
    Showers and
    Areas Dense
    Fog

  • Tonight

    Tonight: Partly cloudy, with a low around 39. West wind around 6 mph.

    Low: 39 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 57. Calm wind becoming southwest 5 to 9 mph in the morning.

    High: 57 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 38. Southwest wind 3 to 6 mph.

    Low: 38 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 56. Calm wind becoming south 5 to 7 mph in the afternoon.

    High: 56 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 41.

    Low: 41 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Cloudy, with a high near 54.

    High: 54 °F

    Cloudy

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers after 2am. Cloudy, with a low around 45.

    Low: 45 °F

    Cloudy then
    Chance
    Showers

Detailed Forecast

Today
A 40 percent chance of showers, mainly before 11am. Areas of dense fog before 11am. Otherwise, mostly cloudy, with a high near 59. Southwest wind around 10 mph.
Tonight
Partly cloudy, with a low around 39. West wind around 6 mph.
Monday
Sunny, with a high near 57. Calm wind becoming southwest 5 to 9 mph in the morning.
Monday Night
Partly cloudy, with a low around 38. Southwest wind 3 to 6 mph.
Tuesday
Mostly sunny, with a high near 56. Calm wind becoming south 5 to 7 mph in the afternoon.
Tuesday Night
Mostly cloudy, with a low around 41.
Wednesday
Cloudy, with a high near 54.
Wednesday Night
A 40 percent chance of showers after 2am. Cloudy, with a low around 45.
Thursday
Showers likely, mainly after 8am. Cloudy, with a high near 52. Chance of precipitation is 70%.
Thursday Night
Partly cloudy, with a low around 29.
Friday
Mostly sunny, with a high near 43.
Friday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 36.
Saturday
Mostly sunny, with a high near 48.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
4:09 am EDT Mar 8, 2026
Forecast Valid:
6am EDT Mar 8, 2026-6pm EDT Mar 14, 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