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.

Mostly Cloudy

45°F

7°C

Humidity 63%
Wind Speed NE 3 mph
Barometer 30.26 in (1024.8 mb)
Dewpoint 33°F (1°C)
Visibility 10.00 mi
Last update 20 Nov 9:56 am EST
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Today

    Today: Mostly sunny, with a high near 47. North wind around 5 mph becoming calm in the afternoon.

    High: 47 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 35. Calm wind.

    Low: 35 °F

    Increasing
    Clouds

  • Friday

    Friday: Mostly cloudy, with a high near 54. Light south wind becoming southwest 5 to 10 mph in the morning.

    High: 54 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: Rain likely, mainly after 1am. Cloudy, with a low around 42. Southwest wind around 6 mph becoming light and variable. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 42 °F

    Rain Likely

  • Saturday

    Saturday: A 20 percent chance of rain before 1pm. Partly sunny, with a high near 51. North wind 7 to 13 mph.

    High: 51 °F

    Slight Chance
    Rain

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 33.

    Low: 33 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 49.

    High: 49 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 39.

    Low: 39 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 53.

    High: 53 °F

    Mostly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 47. North wind around 5 mph becoming calm in the afternoon.
Tonight
Increasing clouds, with a low around 35. Calm wind.
Friday
Mostly cloudy, with a high near 54. Light south wind becoming southwest 5 to 10 mph in the morning.
Friday Night
Rain likely, mainly after 1am. Cloudy, with a low around 42. Southwest wind around 6 mph becoming light and variable. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
A 20 percent chance of rain before 1pm. Partly sunny, with a high near 51. North wind 7 to 13 mph.
Saturday Night
Partly cloudy, with a low around 33.
Sunday
Mostly sunny, with a high near 49.
Sunday Night
Partly cloudy, with a low around 39.
Monday
Mostly sunny, with a high near 53.
Monday Night
Mostly cloudy, with a low around 39.
Tuesday
A 30 percent chance of rain. Mostly cloudy, with a high near 55.
Tuesday Night
Rain likely. Mostly cloudy, with a low around 44. Chance of precipitation is 60%.
Wednesday
A 40 percent chance of rain. Partly sunny, with a high near 59.
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.78°N 73.09°W (Elev. 49 ft)
Last Update:
12:34 am EST Nov 20, 2025
Forecast Valid:
10am EST Nov 20, 2025-6pm EST Nov 26, 2025
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation