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.

Mostly Cloudy and Breezy

64°F

18°C

Humidity 26%
Wind Speed N 21 G 37 mph
Barometer 30.22 in (1023.4 mb)
Dewpoint 28°F (-2°C)
Visibility 10.00 mi
Last update 20 Apr 12:56 pm EDT
Extended Forecast for

Port Jefferson NYSimilar City Names

  • This Afternoon

    This Afternoon: Sunny, with a steady temperature around 62. Breezy, with a northwest wind 17 to 20 mph, with gusts as high as 31 mph.

    High: 62 °F

    Sunny and
    Breezy

  • Tonight

    Tonight: Partly cloudy, with a low around 42. North wind 5 to 7 mph.

    Low: 42 °F

    Partly Cloudy

  • Monday

    Monday: Increasing clouds, with a high near 56. East wind 5 to 10 mph becoming south in the afternoon.

    High: 56 °F

    Increasing
    Clouds

  • Monday Night

    Monday Night: Showers likely, mainly after 2am. Cloudy, with a low around 49. South wind 9 to 11 mph. Chance of precipitation is 70%.

    Low: 49 °F

    Chance
    Showers then
    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 75. Southwest wind 8 to 14 mph. Chance of precipitation is 60%.

    High: 75 °F

    Showers
    Likely then
    Slight Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 48.

    Low: 48 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 63.

    High: 63 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 48.

    Low: 48 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 63.

    High: 63 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Sunny, with a steady temperature around 62. Breezy, with a northwest wind 17 to 20 mph, with gusts as high as 31 mph.
Tonight
Partly cloudy, with a low around 42. North wind 5 to 7 mph.
Monday
Increasing clouds, with a high near 56. East wind 5 to 10 mph becoming south in the afternoon.
Monday Night
Showers likely, mainly after 2am. Cloudy, with a low around 49. South wind 9 to 11 mph. Chance of precipitation is 70%.
Tuesday
Showers likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 75. Southwest wind 8 to 14 mph. Chance of precipitation is 60%.
Tuesday Night
Partly cloudy, with a low around 48.
Wednesday
Mostly sunny, with a high near 63.
Wednesday Night
Partly cloudy, with a low around 48.
Thursday
Mostly sunny, with a high near 63.
Thursday Night
Partly cloudy, with a low around 48.
Friday
Partly sunny, with a high near 62.
Friday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 51.
Saturday
A 40 percent chance of showers. Mostly cloudy, with a high near 63.
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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:
10:10 am EDT Apr 20, 2025
Forecast Valid:
1pm EDT Apr 20, 2025-6pm EDT Apr 26, 2025
 
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Additional Resources

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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