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.

Mostly Cloudy

69°F

21°C

Humidity 93%
Wind Speed NW 6 mph
Barometer 30.01 in (1016.1 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 20 May 11:56 pm EDT
Extended Forecast for

Islip NY

  • Overnight

    Overnight: A 50 percent chance of showers. Mostly cloudy, with a low around 55. North wind 3 to 6 mph.

    Low: 55 °F

    Chance
    Showers

  • Thursday

    Thursday: Showers likely, mainly before 11am. Cloudy, with a high near 62. Northeast wind 8 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 62 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: Cloudy during the early evening, then gradual clearing, with a low around 50. Light and variable wind.

    Low: 50 °F

    Gradual
    Clearing

  • Friday

    Friday: Increasing clouds, with a high near 64. East wind 8 to 11 mph.

    High: 64 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: A 30 percent chance of showers after 2am. Cloudy, with a low around 50. East wind around 5 mph.

    Low: 50 °F

    Mostly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: Showers, mainly after 8am. High near 59. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 59 °F

    Showers

  • Saturday Night

    Saturday Night: Showers. Low around 50. Chance of precipitation is 80%.

    Low: 50 °F

    Showers

  • Sunday

    Sunday: Showers likely, mainly before 2pm. Cloudy, with a high near 66. Chance of precipitation is 70%.

    High: 66 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: A 50 percent chance of showers. Cloudy, with a low around 54.

    Low: 54 °F

    Chance
    Showers

Detailed Forecast

Overnight
A 50 percent chance of showers. Mostly cloudy, with a low around 55. North wind 3 to 6 mph.
Thursday
Showers likely, mainly before 11am. Cloudy, with a high near 62. Northeast wind 8 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday Night
Cloudy during the early evening, then gradual clearing, with a low around 50. Light and variable wind.
Friday
Increasing clouds, with a high near 64. East wind 8 to 11 mph.
Friday Night
A 30 percent chance of showers after 2am. Cloudy, with a low around 50. East wind around 5 mph.
Saturday
Showers, mainly after 8am. High near 59. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday Night
Showers. Low around 50. Chance of precipitation is 80%.
Sunday
Showers likely, mainly before 2pm. Cloudy, with a high near 66. Chance of precipitation is 70%.
Sunday Night
A 50 percent chance of showers. Cloudy, with a low around 54.
Memorial Day
A 40 percent chance of showers before 2pm. Cloudy, with a high near 70.
Monday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 56.
Tuesday
Partly sunny, with a high near 74.
Tuesday Night
Mostly cloudy, with a low around 58.
Wednesday
Partly sunny, with a high near 77.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Islip NY
 40.73°N 73.22°W (Elev. 7 ft)
Last Update:
9:00 pm EDT May 20, 2026
Forecast Valid:
12am EDT May 21, 2026-6pm EDT May 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