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.

Mostly Cloudy

30°F

-1°C

Humidity 45%
Wind Speed SW 10 G 22 mph
Barometer 30.40 in (1029.5 mb)
Dewpoint 11°F (-12°C)
Visibility 10.00 mi
Wind Chill21°F (-6°C)
Last update 21 Jan 1:56 pm EST
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • This Afternoon

    This Afternoon: Mostly cloudy, with a high near 39. Wind chill values between 20 and 25. South wind around 10 mph, with gusts as high as 21 mph.

    High: 39 °F

    Mostly Cloudy

  • Tonight

    Tonight: A slight chance of rain before 10pm, then a chance of snow between 10pm and 1am. Mostly cloudy, with a steady temperature around 37. Southwest wind around 10 mph, with gusts as high as 24 mph. Chance of precipitation is 30%.

    Low: 37 °F

    Chance
    Rain/Snow
    then Chance
    Snow

  • Thursday

    Thursday: Mostly sunny, with a high near 44. West wind 9 to 14 mph, with gusts as high as 25 mph.

    High: 44 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 25. West wind 6 to 8 mph, with gusts as high as 20 mph.

    Low: 25 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 35. West wind 6 to 13 mph, with gusts as high as 24 mph.

    High: 35 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 10.

    Low: 10 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny and cold, with a high near 18.

    High: 18 °F

    Cold

  • Saturday Night

    Saturday Night: Snow likely after 1am. Mostly cloudy, with a low around 10. Chance of precipitation is 60%.

    Low: 10 °F

    Mostly Cloudy
    then Snow
    Likely

  • Sunday

    Sunday: Snow. High near 25. Chance of precipitation is 90%.

    High: 25 °F

    Snow

Detailed Forecast

This Afternoon
Mostly cloudy, with a high near 39. Wind chill values between 20 and 25. South wind around 10 mph, with gusts as high as 21 mph.
Tonight
A slight chance of rain before 10pm, then a chance of snow between 10pm and 1am. Mostly cloudy, with a steady temperature around 37. Southwest wind around 10 mph, with gusts as high as 24 mph. Chance of precipitation is 30%.
Thursday
Mostly sunny, with a high near 44. West wind 9 to 14 mph, with gusts as high as 25 mph.
Thursday Night
Partly cloudy, with a low around 25. West wind 6 to 8 mph, with gusts as high as 20 mph.
Friday
Partly sunny, with a high near 35. West wind 6 to 13 mph, with gusts as high as 24 mph.
Friday Night
Partly cloudy, with a low around 10.
Saturday
Partly sunny and cold, with a high near 18.
Saturday Night
Snow likely after 1am. Mostly cloudy, with a low around 10. Chance of precipitation is 60%.
Sunday
Snow. High near 25. Chance of precipitation is 90%.
Sunday Night
Snow. Low around 18. Chance of precipitation is 80%.
Monday
A 50 percent chance of snow. Mostly cloudy, with a high near 27.
Monday Night
Partly cloudy, with a low around 12.
Tuesday
Mostly sunny, with a high near 24.
Basemap Options
Click map to change the forecast location
Loading map...
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:
12:34 pm EST Jan 21, 2026
Forecast Valid:
2pm EST Jan 21, 2026-6pm EST Jan 27, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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