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.

Overcast

48°F

9°C

Humidity 86%
Wind Speed Calm
Barometer 29.94 in (1014.0 mb)
Dewpoint 44°F (7°C)
Visibility 10.00 mi
Last update 21 Nov 9:56 pm EST
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Tonight

    Tonight: Showers likely, mainly after 4am. Mostly cloudy, with a low around 43. Light west wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 43 °F

    Mostly Cloudy
    then Showers
    Likely

  • Saturday

    Saturday: Showers likely before 10am, then a chance of rain between 10am and 1pm. Cloudy through mid morning, then gradual clearing, with a high near 52. North wind 5 to 11 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.

    High: 52 °F

    Showers
    Likely then
    Chance Rain

  • Saturday Night

    Saturday Night: Widespread frost, mainly after 3am. Otherwise, partly cloudy, with a low around 34. North wind 5 to 9 mph.

    Low: 34 °F

    Mostly Clear
    then Frost

  • Sunday

    Sunday: Areas of frost before 8am. Otherwise, mostly sunny, with a high near 50. Light and variable wind becoming southwest 6 to 11 mph in the morning.

    High: 50 °F

    Areas Frost
    then Mostly
    Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 39. West wind around 10 mph.

    Low: 39 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 53.

    High: 53 °F

    Sunny

  • Monday Night

    Monday Night: Increasing clouds, with a low around 39.

    Low: 39 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: A 30 percent chance of rain after 1pm. Cloudy, with a high near 57.

    High: 57 °F

    Mostly Cloudy
    then Chance
    Rain

  • Tuesday Night

    Tuesday Night: Rain likely. Cloudy, with a low around 48. Chance of precipitation is 70%.

    Low: 48 °F

    Rain Likely

Detailed Forecast

Tonight
Showers likely, mainly after 4am. Mostly cloudy, with a low around 43. Light west wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Saturday
Showers likely before 10am, then a chance of rain between 10am and 1pm. Cloudy through mid morning, then gradual clearing, with a high near 52. North wind 5 to 11 mph. Chance of precipitation is 70%. New precipitation amounts of less than a tenth of an inch possible.
Saturday Night
Widespread frost, mainly after 3am. Otherwise, partly cloudy, with a low around 34. North wind 5 to 9 mph.
Sunday
Areas of frost before 8am. Otherwise, mostly sunny, with a high near 50. Light and variable wind becoming southwest 6 to 11 mph in the morning.
Sunday Night
Partly cloudy, with a low around 39. West wind around 10 mph.
Monday
Sunny, with a high near 53.
Monday Night
Increasing clouds, with a low around 39.
Tuesday
A 30 percent chance of rain after 1pm. Cloudy, with a high near 57.
Tuesday Night
Rain likely. Cloudy, with a low around 48. Chance of precipitation is 70%.
Wednesday
A 40 percent chance of rain. Mostly cloudy, with a high near 60.
Wednesday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 41.
Thanksgiving Day
Mostly sunny, with a high near 52.
Thursday Night
Partly cloudy, with a low around 34.
Friday
Mostly sunny, with a high near 47.
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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:
3:11 pm EST Nov 21, 2025
Forecast Valid:
10pm EST Nov 21, 2025-6pm EST Nov 28, 2025
 
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