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.

Fog/Mist

71°F

22°C

Humidity 94%
Wind Speed SE 5 mph
Barometer 30.02 in (1016.6 mb)
Dewpoint 69°F (21°C)
Visibility 6.00 mi
Last update 1 Sep 10:56 am EDT
Extended Forecast for

Mount Sinai NY

  • Today

    Today: Showers likely before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers and possibly a thunderstorm after 5pm. Some of the storms could be severe. High near 77. Southwest wind around 6 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 77 °F

    Severe
    Thunderstorms

  • Tonight

    Tonight: Showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Some of the storms could be severe. Low around 66. East wind 6 to 8 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 66 °F

    Severe
    Thunderstorms
    then Chance
    Showers

  • Wednesday

    Wednesday: A slight chance of showers between 11am and 5pm. Cloudy, with a high near 74. East wind around 11 mph. Chance of precipitation is 20%.

    High: 74 °F

    Slight Chance
    Showers

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm, mainly after 2am. Mostly cloudy, with a low around 65. East wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 65 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Thursday

    Thursday: Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 82. Southwest wind 6 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Showers
    Likely then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 75.

    High: 75 °F

    Sunny

Detailed Forecast

Today
Showers likely before 2pm, then a chance of showers and thunderstorms between 2pm and 5pm, then showers and possibly a thunderstorm after 5pm. Some of the storms could be severe. High near 77. Southwest wind around 6 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tonight
Showers and thunderstorms before 11pm, then a chance of showers between 11pm and 2am. Some of the storms could be severe. Low around 66. East wind 6 to 8 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday
A slight chance of showers between 11am and 5pm. Cloudy, with a high near 74. East wind around 11 mph. Chance of precipitation is 20%.
Wednesday Night
Showers likely and possibly a thunderstorm, mainly after 2am. Mostly cloudy, with a low around 65. East wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday
Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 82. Southwest wind 6 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.
Friday
Sunny, with a high near 81.
Friday Night
Partly cloudy, with a low around 64.
Saturday
Sunny, with a high near 75.
Saturday Night
Partly cloudy, with a low around 60.
Sunday
Mostly sunny, with a high near 73.
Sunday Night
Partly cloudy, with a low around 60.
Labor Day
Mostly sunny, with a high near 75.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Sinai NY
 40.93°N 73.03°W (Elev. 151 ft)
Last Update:
5:43 am EDT Sep 1, 2026
Forecast Valid:
11am EDT Sep 1, 2026-6pm EDT Sep 7, 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