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

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

A Few Clouds

42°F

6°C

Humidity 43%
Wind Speed N 13 mph
Barometer 30.28 in (1025.4 mb)
Dewpoint 21°F (-6°C)
Visibility 10.00 mi
Wind Chill35°F (2°C)
Last update 20 Apr 9:56 pm EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

Freeze Warning April 21, 12:00am until April 21, 09:00am
Click here for hazard details and duration
Freeze Warning

  • Tonight

    Tonight: Mostly clear, with a low around 31. North wind 7 to 10 mph, with gusts as high as 20 mph.

    Low: 31 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 51. North wind around 6 mph becoming south in the afternoon.

    High: 51 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers after 2am. Increasing clouds, with a low around 38. South wind around 7 mph.

    Low: 38 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Wednesday

    Wednesday: A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 55. South wind around 10 mph.

    High: 55 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 43. Light east wind.

    Low: 43 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 63.

    High: 63 °F

    Mostly Sunny

  • Thursday Night

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

    Low: 44 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 59.

    High: 59 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 44.

    Low: 44 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 31. North wind 7 to 10 mph, with gusts as high as 20 mph.
Tuesday
Sunny, with a high near 51. North wind around 6 mph becoming south in the afternoon.
Tuesday Night
A 20 percent chance of showers after 2am. Increasing clouds, with a low around 38. South wind around 7 mph.
Wednesday
A 40 percent chance of showers, mainly before noon. Mostly cloudy, with a high near 55. South wind around 10 mph.
Wednesday Night
Mostly cloudy, with a low around 43. Light east wind.
Thursday
Mostly sunny, with a high near 63.
Thursday Night
Mostly cloudy, with a low around 44.
Friday
Mostly sunny, with a high near 59.
Friday Night
Partly cloudy, with a low around 44.
Saturday
A 40 percent chance of showers after 8am. Mostly cloudy, with a high near 54.
Saturday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 43.
Sunday
A 30 percent chance of showers. Mostly cloudy, with a high near 57.
Sunday Night
Mostly cloudy, with a low around 43.
Monday
Partly sunny, with a high near 58.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.78°N 73.09°W (Elev. 49 ft)
Last Update:
6:38 pm EDT Apr 20, 2026
Forecast Valid:
10pm EDT Apr 20, 2026-6pm EDT Apr 27, 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