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.

Fair

31°F

-1°C

Humidity 82%
Wind Speed Calm
Barometer 30.62 in (1037.0 mb)
Dewpoint 26°F (-3°C)
Visibility 10.00 mi
Last update 9 Apr 12:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Overnight

    Overnight: Widespread frost, mainly after 2am. Otherwise, mostly clear, with a low around 32. Calm wind.

    Low: 32 °F

    Frost

  • Thursday

    Thursday: Widespread frost, mainly before 7am. Otherwise, sunny, with a high near 50. Calm wind becoming southeast 5 to 9 mph in the morning.

    High: 50 °F

    Frost then
    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 37. South wind around 6 mph becoming calm in the evening.

    Low: 37 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 56. Light southwest wind becoming south 6 to 11 mph in the morning.

    High: 56 °F

    Sunny

  • Friday Night

    Friday Night: A 20 percent chance of showers after 2am. Mostly cloudy, with a low around 45. South wind 8 to 10 mph.

    Low: 45 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Saturday

    Saturday: Partly sunny, then gradually becoming sunny, with a high near 59.

    High: 59 °F

    Becoming
    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 39.

    Low: 39 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 54.

    High: 54 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 44.

    Low: 44 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Widespread frost, mainly after 2am. Otherwise, mostly clear, with a low around 32. Calm wind.
Thursday
Widespread frost, mainly before 7am. Otherwise, sunny, with a high near 50. Calm wind becoming southeast 5 to 9 mph in the morning.
Thursday Night
Mostly clear, with a low around 37. South wind around 6 mph becoming calm in the evening.
Friday
Sunny, with a high near 56. Light southwest wind becoming south 6 to 11 mph in the morning.
Friday Night
A 20 percent chance of showers after 2am. Mostly cloudy, with a low around 45. South wind 8 to 10 mph.
Saturday
Partly sunny, then gradually becoming sunny, with a high near 59.
Saturday Night
Mostly clear, with a low around 39.
Sunday
Sunny, with a high near 54.
Sunday Night
Mostly cloudy, with a low around 44.
Monday
Mostly cloudy, with a high near 63.
Monday Night
Mostly cloudy, with a low around 54.
Tuesday
Partly sunny, with a high near 70.
Tuesday Night
Mostly cloudy, with a low around 55.
Wednesday
Mostly sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
5:30 pm EDT Apr 8, 2026
Forecast Valid:
1am EDT Apr 9, 2026-6pm EDT Apr 15, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation