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.

Fair

68°F

20°C

Humidity 49%
Wind Speed W 10 mph
Barometer 29.72 in (1006.4 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 20 Jun 1:56 am EDT
Extended Forecast for

Holtsville NY

  • Overnight

    Overnight: Clear, with a low around 64. West wind around 11 mph, with gusts as high as 23 mph.

    Low: 64 °F

    Clear

  • Saturday

    Saturday: Sunny, with a high near 81. Breezy, with a west wind 16 to 20 mph.

    High: 81 °F

    Sunny and
    Breezy then
    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 64. Northwest wind 5 to 7 mph becoming calm in the evening.

    Low: 64 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 80. Light and variable wind becoming southwest 5 to 9 mph in the morning.

    High: 80 °F

    Sunny

  • Sunday Night

    Sunday Night: A 20 percent chance of showers after 2am. Partly cloudy, with a low around 64. Light and variable wind.

    Low: 64 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Monday

    Monday: Showers, mainly after 8am. High near 77. Chance of precipitation is 90%. New precipitation amounts between three quarters and one inch possible.

    High: 77 °F

    Showers
    Likely then
    Showers

  • Monday Night

    Monday Night: Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 90%.

    Low: 65 °F

    Showers

  • Tuesday

    Tuesday: A 30 percent chance of showers before 8am. Mostly sunny, with a high near 80.

    High: 80 °F

    Chance
    Showers then
    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 65.

    Low: 65 °F

    Mostly Clear

Detailed Forecast

Overnight
Clear, with a low around 64. West wind around 11 mph, with gusts as high as 23 mph.
Saturday
Sunny, with a high near 81. Breezy, with a west wind 16 to 20 mph.
Saturday Night
Mostly clear, with a low around 64. Northwest wind 5 to 7 mph becoming calm in the evening.
Sunday
Sunny, with a high near 80. Light and variable wind becoming southwest 5 to 9 mph in the morning.
Sunday Night
A 20 percent chance of showers after 2am. Partly cloudy, with a low around 64. Light and variable wind.
Monday
Showers, mainly after 8am. High near 77. Chance of precipitation is 90%. New precipitation amounts between three quarters and one inch possible.
Monday Night
Showers and possibly a thunderstorm before 2am, then a chance of showers. Low around 65. Chance of precipitation is 90%.
Tuesday
A 30 percent chance of showers before 8am. Mostly sunny, with a high near 80.
Tuesday Night
Mostly clear, with a low around 65.
Wednesday
Sunny, with a high near 83.
Wednesday Night
Mostly clear, with a low around 66.
Thursday
Sunny, with a high near 82.
Thursday Night
Partly cloudy, with a low around 66.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Holtsville NY
 40.82°N 73.05°W (Elev. 112 ft)
Last Update:
2:19 am EDT Jun 20, 2026
Forecast Valid:
2am EDT Jun 20, 2026-6pm EDT Jun 26, 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