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 73 by 5pm. South wind 6 to 11 mph.

    High: 80 °F⇓

    Mostly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 55. Southwest wind 6 to 10 mph.

    Low: 55 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers after 2pm. Mostly sunny, with a high near 80. South wind 6 to 13 mph.

    High: 80 °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 55. Southwest wind 5 to 8 mph. Chance of precipitation is 30%.

    Low: 55 °F

    Chance
    Showers

  • Thursday

    Thursday: Partly sunny, with a high near 74. South wind 5 to 11 mph.

    High: 74 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 55.

    Low: 55 °F

    Mostly Cloudy

  • Friday

    Friday: A 40 percent chance of showers after 2pm. Partly sunny, with a high near 70.

    High: 70 °F

    Mostly Cloudy
    then Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 49.

    Low: 49 °F

    Chance
    Showers then
    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 62.

    High: 62 °F

    Partly Sunny

Detailed Forecast

Today
Mostly sunny, with a temperature falling to around 73 by 5pm. South wind 6 to 11 mph.
Tonight
Partly cloudy, with a low around 55. Southwest wind 6 to 10 mph.
Wednesday
A 20 percent chance of showers after 2pm. Mostly sunny, with a high near 80. South wind 6 to 13 mph.
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 55. Southwest wind 5 to 8 mph. Chance of precipitation is 30%.
Thursday
Partly sunny, with a high near 74. South wind 5 to 11 mph.
Thursday Night
Mostly cloudy, with a low around 55.
Friday
A 40 percent chance of showers after 2pm. Partly sunny, with a high near 70.
Friday Night
A 30 percent chance of showers before 8pm. Mostly cloudy, with a low around 49.
Saturday
Partly sunny, with a high near 62.
Saturday Night
Mostly cloudy, with a low around 49.
Sunday
A 40 percent chance of showers. Mostly cloudy, with a high near 63.
Sunday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 42.
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
 40.81°N 73.11°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

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