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

77°F

25°C

Humidity 69%
Wind Speed SW 8 mph
Barometer 30.23 in (1023.6 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 17 Sep 11:56 am EDT
Extended Forecast for

Sayville NY

  • This Afternoon

    This Afternoon: Scattered showers after 4pm. Mostly sunny, with a high near 78. South wind 10 to 14 mph. Chance of precipitation is 30%.

    High: 78 °F

    Scattered
    Showers

  • Tonight

    Tonight: A 20 percent chance of showers after 10pm. Mostly cloudy, with a low around 68. South wind 9 to 11 mph.

    Low: 68 °F

    Slight Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 79. North wind 8 to 11 mph.

    High: 79 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 58. Northeast wind 9 to 13 mph.

    Low: 58 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 69. Northeast wind 8 to 11 mph.

    High: 69 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 59.

    Low: 59 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Showers. High near 72. Chance of precipitation is 80%.

    High: 72 °F

    Showers

  • Sunday Night

    Sunday Night: Showers, mainly before 2am. Low around 58. Chance of precipitation is 80%.

    Low: 58 °F

    Showers

  • Monday

    Monday: A 30 percent chance of showers before 8am. Partly sunny, with a high near 69.

    High: 69 °F

    Chance
    Showers then
    Partly Sunny

Detailed Forecast

This Afternoon
Scattered showers after 4pm. Mostly sunny, with a high near 78. South wind 10 to 14 mph. Chance of precipitation is 30%.
Tonight
A 20 percent chance of showers after 10pm. Mostly cloudy, with a low around 68. South wind 9 to 11 mph.
Friday
Mostly sunny, with a high near 79. North wind 8 to 11 mph.
Friday Night
Partly cloudy, with a low around 58. Northeast wind 9 to 13 mph.
Saturday
Mostly sunny, with a high near 69. Northeast wind 8 to 11 mph.
Saturday Night
Increasing clouds, with a low around 59.
Sunday
Showers. High near 72. Chance of precipitation is 80%.
Sunday Night
Showers, mainly before 2am. Low around 58. Chance of precipitation is 80%.
Monday
A 30 percent chance of showers before 8am. Partly sunny, with a high near 69.
Monday Night
Mostly cloudy, with a low around 57.
Tuesday
Partly sunny, with a high near 67. Breezy.
Tuesday Night
Partly cloudy, with a low around 56.
Wednesday
Mostly sunny, with a high near 68. Breezy.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sayville NY
 40.73°N 73.07°W (Elev. 16 ft)
Last Update:
11:11 am EDT Sep 17, 2026
Forecast Valid:
12pm EDT Sep 17, 2026-6pm EDT Sep 23, 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