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.

Mostly Cloudy

46°F

8°C

Humidity 51%
Wind Speed NW 8 G 20 mph
Barometer 29.96 in (1014.5 mb)
Dewpoint 29°F (-2°C)
Visibility 10.00 mi
Wind Chill42°F (6°C)
Last update 21 Feb 12:56 pm EST
Extended Forecast for

2 Miles NNW Stony Brook NY

Coastal Flood Watch February 23, 12:00am until February 23, 05:00am
Blizzard Warning February 22, 01:00pm until February 23, 06:00pm
Click here for hazard details and duration
Coastal Flood Watch
Blizzard Warning

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 43. Northwest wind 3 to 6 mph.

    High: 43 °F

    Partly Sunny

  • Tonight

    Tonight: A 40 percent chance of snow after 1am. Mostly cloudy, with a low around 31. Wind chill values between 25 and 30. Light and variable wind becoming east 5 to 9 mph in the evening.

    Low: 31 °F

    Mostly Cloudy
    then Chance
    Snow

  • Sunday

    Sunday: Snow likely, mainly after 4pm. Cloudy, with a high near 36. Wind chill values between 20 and 25. East wind 10 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New snow accumulation of around an inch possible.

    High: 36 °F

    Snow Likely

  • Sunday Night

    Sunday Night: Snow. The snow could be heavy at times. Areas of blowing snow after 10pm. Steady temperature around 32. Wind chill values between 15 and 20. Windy, with a north wind 22 to 27 mph increasing to 32 to 37 mph after midnight. Winds could gust as high as 48 mph. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.

    Low: 32 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday

    Monday: Snow. The snow could be heavy at times. Areas of blowing snow. Steady temperature around 31. Windy, with a north wind 28 to 37 mph, with gusts as high as 50 mph. Chance of precipitation is 100%. New snow accumulation of 4 to 8 inches possible.

    High: 31 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday Night

    Monday Night: A 40 percent chance of snow before 10pm. Areas of blowing snow before 1am. Mostly cloudy, with a low around 23. Blustery.

    Low: 23 °F

    Chance Snow
    and Areas
    Blowing Snow
    then Areas
    Blowing Snow

  • Tuesday

    Tuesday: Mostly sunny, with a high near 30.

    High: 30 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 19.

    Low: 19 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 39. Chance of precipitation is 50%.

    High: 39 °F

    Chance
    Rain/Snow

Detailed Forecast

This Afternoon
Partly sunny, with a high near 43. Northwest wind 3 to 6 mph.
Tonight
A 40 percent chance of snow after 1am. Mostly cloudy, with a low around 31. Wind chill values between 25 and 30. Light and variable wind becoming east 5 to 9 mph in the evening.
Sunday
Snow likely, mainly after 4pm. Cloudy, with a high near 36. Wind chill values between 20 and 25. East wind 10 to 18 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New snow accumulation of around an inch possible.
Sunday Night
Snow. The snow could be heavy at times. Areas of blowing snow after 10pm. Steady temperature around 32. Wind chill values between 15 and 20. Windy, with a north wind 22 to 27 mph increasing to 32 to 37 mph after midnight. Winds could gust as high as 48 mph. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.
Monday
Snow. The snow could be heavy at times. Areas of blowing snow. Steady temperature around 31. Windy, with a north wind 28 to 37 mph, with gusts as high as 50 mph. Chance of precipitation is 100%. New snow accumulation of 4 to 8 inches possible.
Monday Night
A 40 percent chance of snow before 10pm. Areas of blowing snow before 1am. Mostly cloudy, with a low around 23. Blustery.
Tuesday
Mostly sunny, with a high near 30.
Tuesday Night
Mostly cloudy, with a low around 19.
Wednesday
A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 39. Chance of precipitation is 50%.
Wednesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 32.
Thursday
A 40 percent chance of rain. Partly sunny, with a high near 41.
Thursday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 31.
Friday
A 40 percent chance of rain. Partly sunny, with a high near 39.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
1:10 pm EST Feb 21, 2026
Forecast Valid:
1pm EST Feb 21, 2026-6pm EST Feb 27, 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