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.

Fair

54°F

12°C

Humidity 67%
Wind Speed W 9 mph
Barometer 29.89 in (1012.0 mb)
Dewpoint 43°F (6°C)
Visibility 10.00 mi
Wind Chill51°F (11°C)
Last update 10 Nov 9:56 pm EST
Extended Forecast for

Mount Sinai NY

  • Tonight

    Tonight: Clear, with a low around 45. West wind 7 to 10 mph.

    Low: 45 °F

    Clear

  • Veterans Day

    Veterans Day: Mostly sunny, with a high near 59. West wind 5 to 7 mph becoming southwest in the afternoon.

    High: 59 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of rain after 4am. Mostly cloudy, with a low around 45. Calm wind becoming southeast 5 to 7 mph after midnight.

    Low: 45 °F

    Mostly Cloudy
    then Slight
    Chance Rain

  • Thursday

    Thursday: Rain, mainly after 1pm. High near 59. East wind 9 to 14 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 59 °F

    Chance Rain
    then Rain

  • Thursday Night

    Thursday Night: Rain. Low around 45. Northeast wind 10 to 14 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 45 °F

    Rain

  • Friday

    Friday: Rain. High near 51. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 51 °F

    Rain

  • Friday Night

    Friday Night: A 50 percent chance of rain. Mostly cloudy, with a low around 36.

    Low: 36 °F

    Chance Rain

  • Saturday

    Saturday: A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 48.

    High: 48 °F

    Chance Rain

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 36.

    Low: 36 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Clear, with a low around 45. West wind 7 to 10 mph.
Veterans Day
Mostly sunny, with a high near 59. West wind 5 to 7 mph becoming southwest in the afternoon.
Wednesday Night
A 20 percent chance of rain after 4am. Mostly cloudy, with a low around 45. Calm wind becoming southeast 5 to 7 mph after midnight.
Thursday
Rain, mainly after 1pm. High near 59. East wind 9 to 14 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday Night
Rain. Low around 45. Northeast wind 10 to 14 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Rain. High near 51. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 36.
Saturday
A 30 percent chance of rain before 1pm. Mostly cloudy, with a high near 48.
Saturday Night
Mostly cloudy, with a low around 36.
Sunday
Mostly sunny, with a high near 51.
Sunday Night
Partly cloudy, with a low around 35.
Monday
Mostly sunny, with a high near 51.
Monday Night
Partly cloudy, with a low around 35.
Tuesday
Sunny, with a high near 51.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Sinai NY
 40.93°N 73°W (Elev. 141 ft)
Last Update:
6:08 pm EST Nov 10, 2026
Forecast Valid:
10pm EST Nov 10, 2026-6pm EST Nov 17, 2026
 
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Additional Resources

Radar & Satellite Image

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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