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

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

A Few Clouds

77°F

25°C

Humidity 50%
Wind Speed S 7 mph
Barometer 29.99 in (1015.7 mb)
Dewpoint 57°F (14°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 14 Apr 10:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Today

    Today: Mostly sunny, with a temperature falling to around 71 by 5pm. South wind 5 to 10 mph.

    High: 80 °F⇓

    Mostly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 54. Southwest wind 5 to 8 mph.

    Low: 54 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers after 2pm. Mostly sunny, with a high near 79. Light southwest wind becoming south 5 to 10 mph in the morning.

    High: 79 °F

    Mostly Sunny
    then Slight
    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph. Chance of precipitation is 30%.

    Low: 54 °F

    Chance
    Showers

  • Thursday

    Thursday: Partly sunny, with a high near 74. Light southwest wind becoming south 5 to 9 mph in the morning.

    High: 74 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 54.

    Low: 54 °F

    Mostly Cloudy

  • Friday

    Friday: A 40 percent chance of showers. Partly sunny, with a high near 70.

    High: 70 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 49.

    Low: 49 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 61.

    High: 61 °F

    Partly Sunny

Detailed Forecast

Today
Mostly sunny, with a temperature falling to around 71 by 5pm. South wind 5 to 10 mph.
Tonight
Partly cloudy, with a low around 54. Southwest wind 5 to 8 mph.
Wednesday
A 20 percent chance of showers after 2pm. Mostly sunny, with a high near 79. Light southwest wind becoming south 5 to 10 mph in the morning.
Wednesday Night
A chance of showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Mostly cloudy, with a low around 54. Southwest wind 3 to 6 mph. Chance of precipitation is 30%.
Thursday
Partly sunny, with a high near 74. Light southwest wind becoming south 5 to 9 mph in the morning.
Thursday Night
Mostly cloudy, with a low around 54.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 70.
Friday Night
Mostly cloudy, with a low around 49.
Saturday
Partly sunny, with a high near 61.
Saturday Night
Mostly cloudy, with a low around 47.
Sunday
A 40 percent chance of showers. Mostly cloudy, with a high near 61.
Sunday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 43.
Monday
Mostly sunny, with a high near 54.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.8°N 73.09°W (Elev. 98 ft)
Last Update:
10:17 am EDT Apr 14, 2026
Forecast Valid:
11am EDT Apr 14, 2026-6pm EDT Apr 20, 2026
 
Forecast Discussion
 
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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