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.

Fair

74°F

23°C

Humidity 79%
Wind Speed Calm
Barometer 30.01 in (1015.9 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 10 Aug 12:56 am EDT
Extended Forecast for

Port Jefferson Station NY

Heat Advisory August 10, 01:18am until August 10, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 10, 01:18am until August 10, 07:00pm

    NOW until 7:00pm Mon

    Heat Advisory

  • Overnight

    Low: 70 °F

    Mostly Clear

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Sunny, with a high near 89. Calm wind becoming southwest 5 to 9 mph in the afternoon.

    High: 89 °F

    Sunny then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 30 percent chance of showers and thunderstorms before 11pm. Cloudy during the early evening, then gradual clearing, with a low around 73. West wind around 8 mph.

    Low: 73 °F

    Chance
    T-storms then
    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 87. West wind around 9 mph.

    High: 87 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 68. Northwest wind 5 to 7 mph.

    Low: 68 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 85.

    High: 85 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms after 2am. Partly cloudy, with a low around 70.

    Low: 70 °F

    Partly Cloudy
    then Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms before 8am, then a chance of showers between 8am and 2pm. Mostly sunny, with a high near 86. Chance of precipitation is 30%.

    High: 86 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Overnight
Mostly clear, with a low around 70. Light northeast wind.
Monday
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Sunny, with a high near 89. Calm wind becoming southwest 5 to 9 mph in the afternoon.
Monday Night
A 30 percent chance of showers and thunderstorms before 11pm. Cloudy during the early evening, then gradual clearing, with a low around 73. West wind around 8 mph.
Tuesday
Mostly sunny, with a high near 87. West wind around 9 mph.
Tuesday Night
Partly cloudy, with a low around 68. Northwest wind 5 to 7 mph.
Wednesday
Mostly sunny, with a high near 85.
Wednesday Night
A 40 percent chance of showers and thunderstorms after 2am. Partly cloudy, with a low around 70.
Thursday
A chance of showers and thunderstorms before 8am, then a chance of showers between 8am and 2pm. Mostly sunny, with a high near 86. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 66.
Friday
Sunny, with a high near 81.
Friday Night
Mostly clear, with a low around 64.
Saturday
Sunny, with a high near 80.
Saturday Night
Partly cloudy, with a low around 64.
Sunday
Mostly sunny, with a high near 79.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson Station NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
2:26 pm EDT Aug 9, 2026
Forecast Valid:
1am EDT Aug 10, 2026-6pm EDT Aug 16, 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