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.

A Few Clouds

60°F

16°C

Humidity 50%
Wind Speed SW 10 mph
Barometer 29.88 in (1011.8 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 11 Nov 1:56 pm EST
Extended Forecast for

Mount Sinai NY

  • Veterans Day

    Veterans Day: Mostly sunny, with a high near 61. Southwest wind 5 to 7 mph.

    High: 61 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 49. Light and variable wind becoming east 5 to 7 mph after midnight.

    Low: 49 °F

    Increasing
    Clouds

  • Thursday

    Thursday: Showers, mainly after 1pm. High near 59. East wind 8 to 15 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 59 °F

    Slight Chance
    Showers then
    Showers

  • Thursday Night

    Thursday Night: Rain, mainly after 1am. Low around 41. Northeast wind around 17 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 41 °F

    Rain

  • Friday

    Friday: Rain, mainly before 4pm. High near 48. North wind 14 to 18 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 48 °F

    Rain

  • Friday Night

    Friday Night: A 30 percent chance of rain before 10pm. Mostly cloudy, with a low around 38.

    Low: 38 °F

    Chance Rain
    then Mostly
    Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 48.

    High: 48 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 38.

    Low: 38 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 51.

    High: 51 °F

    Mostly Sunny

Detailed Forecast

Veterans Day
Mostly sunny, with a high near 61. Southwest wind 5 to 7 mph.
Tonight
Increasing clouds, with a low around 49. Light and variable wind becoming east 5 to 7 mph after midnight.
Thursday
Showers, mainly after 1pm. High near 59. East wind 8 to 15 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Rain, mainly after 1am. Low around 41. Northeast wind around 17 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Rain, mainly before 4pm. High near 48. North wind 14 to 18 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday Night
A 30 percent chance of rain before 10pm. Mostly cloudy, with a low around 38.
Saturday
Partly sunny, with a high near 48.
Saturday Night
Partly cloudy, with a low around 38.
Sunday
Mostly sunny, with a high near 51.
Sunday Night
Partly cloudy, with a low around 38.
Monday
Sunny, with a high near 50.
Monday Night
Mostly clear, with a low around 38.
Tuesday
Sunny, with a high near 50.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Sinai NY
 40.95°N 73.02°W (Elev. 56 ft)
Last Update:
1:27 pm EST Nov 11, 2026
Forecast Valid:
2pm EST Nov 11, 2026-6pm EST Nov 17, 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