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

79°F

26°C

Humidity 50%
Wind Speed NW 12 mph
Barometer 30.03 in (1016.8 mb)
Dewpoint 59°F (15°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 18 Sep 2:56 pm EDT
Extended Forecast for

Islip NY

  • Tonight

    Tonight: Partly cloudy, with a low around 56. Northeast wind 6 to 10 mph, with gusts as high as 20 mph.

    Low: 56 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 70. Northeast wind around 11 mph becoming east in the afternoon. Winds could gust as high as 21 mph.

    High: 70 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 58. Southeast wind around 7 mph.

    Low: 58 °F

    Mostly Cloudy

  • Sunday

    Sunday: A slight chance of showers, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 71. Southeast wind 10 to 16 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    High: 71 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Sunday Night

    Sunday Night: Showers and possibly a thunderstorm before 2am, then showers likely. Low around 60. Southwest wind around 9 mph becoming northwest after midnight. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.

    Low: 60 °F

    Showers

  • Monday

    Monday: Showers likely, mainly before 8am. Mostly cloudy, with a high near 69. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    High: 69 °F

    Showers
    Likely

  • Monday Night

    Monday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 55.

    Low: 55 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A 30 percent chance of showers. Mostly cloudy, with a high near 66. Breezy.

    High: 66 °F

    Chance
    Showers and
    Breezy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 54.

    Low: 54 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Partly cloudy, with a low around 56. Northeast wind 6 to 10 mph, with gusts as high as 20 mph.
Saturday
Mostly sunny, with a high near 70. Northeast wind around 11 mph becoming east in the afternoon. Winds could gust as high as 21 mph.
Saturday Night
Mostly cloudy, with a low around 58. Southeast wind around 7 mph.
Sunday
A slight chance of showers, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 71. Southeast wind 10 to 16 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Sunday Night
Showers and possibly a thunderstorm before 2am, then showers likely. Low around 60. Southwest wind around 9 mph becoming northwest after midnight. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.
Monday
Showers likely, mainly before 8am. Mostly cloudy, with a high near 69. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Monday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 55.
Tuesday
A 30 percent chance of showers. Mostly cloudy, with a high near 66. Breezy.
Tuesday Night
Mostly cloudy, with a low around 54.
Wednesday
Mostly cloudy, with a high near 65. Breezy.
Wednesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 54. Breezy.
Thursday
A 40 percent chance of showers. Mostly cloudy, with a high near 65. Breezy.
Thursday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 54.
Friday
A 30 percent chance of showers. Partly sunny, with a high near 68.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip NY
 40.73°N 73.22°W (Elev. 7 ft)
Last Update:
3:10 pm EDT Sep 18, 2026
Forecast Valid:
3pm EDT Sep 18, 2026-6pm EDT Sep 25, 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