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.

Partly Cloudy

79°F

26°C

Humidity 54%
Wind Speed NW 10 mph
Barometer 30.04 in (1017.1 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 18 Sep 1:56 pm EDT
Extended Forecast for

Nissequogue NY

  • This Afternoon

    This Afternoon: Sunny, with a high near 79. North wind around 9 mph.

    High: 79 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 59. Northeast wind 10 to 16 mph.

    Low: 59 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 68. Northeast wind 6 to 13 mph.

    High: 68 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 59. Southeast wind around 8 mph.

    Low: 59 °F

    Partly Cloudy

  • Sunday

    Sunday: Showers, mainly after 2pm. High near 70. South wind 8 to 11 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 70 °F

    Chance
    Showers then
    Showers

  • Sunday Night

    Sunday Night: Showers. Low around 62. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.

    Low: 62 °F

    Showers

  • Monday

    Monday: Showers likely, mainly before 8am. Mostly cloudy, with a high near 68. Chance of precipitation is 60%.

    High: 68 °F

    Showers
    Likely

  • Monday Night

    Monday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 58. Breezy.

    Low: 58 °F

    Chance
    Showers and
    Breezy

  • Tuesday

    Tuesday: A 40 percent chance of showers. Mostly cloudy, with a high near 64. Breezy.

    High: 64 °F

    Chance
    Showers and
    Breezy

Detailed Forecast

This Afternoon
Sunny, with a high near 79. North wind around 9 mph.
Tonight
Partly cloudy, with a low around 59. Northeast wind 10 to 16 mph.
Saturday
Mostly sunny, with a high near 68. Northeast wind 6 to 13 mph.
Saturday Night
Partly cloudy, with a low around 59. Southeast wind around 8 mph.
Sunday
Showers, mainly after 2pm. High near 70. South wind 8 to 11 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Sunday Night
Showers. Low around 62. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.
Monday
Showers likely, mainly before 8am. Mostly cloudy, with a high near 68. Chance of precipitation is 60%.
Monday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 58. Breezy.
Tuesday
A 40 percent chance of showers. Mostly cloudy, with a high near 64. Breezy.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 56. Breezy.
Wednesday
A 30 percent chance of showers. Mostly cloudy, with a high near 65. Breezy.
Wednesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 56. Breezy.
Thursday
A 30 percent chance of showers. Partly sunny, with a high near 66. Breezy.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Nissequogue NY
 40.92°N 73.18°W (Elev. 23 ft)
Last Update:
11:03 am EDT Sep 18, 2026
Forecast Valid:
2pm EDT Sep 18, 2026-6pm EDT Sep 24, 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