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

78°F

26°C

Humidity 33%
Wind Speed NW 10 mph
Barometer 29.87 in (1011.3 mb)
Dewpoint 47°F (8°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 21 Jun 10:56 am EDT
Extended Forecast for

Islandia NY

  • Today

    Today: Mostly sunny, with a steady temperature around 79. Northwest wind 5 to 9 mph becoming southwest in the afternoon.

    High: 79 °F

    Mostly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 63. Light and variable wind.

    Low: 63 °F

    Partly Cloudy

  • Monday

    Monday: Showers likely and possibly a thunderstorm, mainly after 2pm. Increasing clouds, with a high near 76. Light east wind becoming southeast 8 to 13 mph in the morning. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 76 °F

    Showers
    Likely

  • Monday Night

    Monday Night: Showers and possibly a thunderstorm. Low around 65. Southwest wind 8 to 11 mph, with gusts as high as 24 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 65 °F

    Showers

  • Tuesday

    Tuesday: A 50 percent chance of showers. Partly sunny, with a high near 80. North wind 7 to 9 mph.

    High: 80 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 83.

    High: 83 °F

    Sunny

Detailed Forecast

Today
Mostly sunny, with a steady temperature around 79. Northwest wind 5 to 9 mph becoming southwest in the afternoon.
Tonight
Partly cloudy, with a low around 63. Light and variable wind.
Monday
Showers likely and possibly a thunderstorm, mainly after 2pm. Increasing clouds, with a high near 76. Light east wind becoming southeast 8 to 13 mph in the morning. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Monday Night
Showers and possibly a thunderstorm. Low around 65. Southwest wind 8 to 11 mph, with gusts as high as 24 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Tuesday
A 50 percent chance of showers. Partly sunny, with a high near 80. North wind 7 to 9 mph.
Tuesday Night
Partly cloudy, with a low around 64.
Wednesday
Sunny, with a high near 79.
Wednesday Night
Mostly clear, with a low around 65.
Thursday
Sunny, with a high near 83.
Thursday Night
A 30 percent chance of showers after 2am. Partly cloudy, with a low around 66.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 81.
Friday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 67.
Saturday
Mostly sunny, with a high near 86.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islandia NY
 40.81°N 73.17°W (Elev. 161 ft)
Last Update:
2:19 am EDT Jun 21, 2026
Forecast Valid:
11am EDT Jun 21, 2026-6pm EDT Jun 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