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

66°F

19°C

Humidity 90%
Wind Speed NW 5 mph
Barometer 30.02 in (1016.4 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 4 Aug 2:56 am EDT
Extended Forecast for

Holtsville NY

  • Overnight

    Overnight: Partly cloudy, with a low around 65. North wind around 5 mph.

    Low: 65 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 82. North wind around 6 mph becoming light and variable.

    High: 82 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 65. Light and variable wind.

    Low: 65 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 82. Calm wind becoming south 5 to 7 mph in the afternoon.

    High: 82 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 71. South wind around 6 mph.

    Low: 71 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Thursday

    Thursday: Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 73.

    Low: 73 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 88.

    High: 88 °F

    Mostly Sunny

  • Friday Night

    Friday Night: A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.

    Low: 72 °F

    Chance
    Showers

Detailed Forecast

Overnight
Partly cloudy, with a low around 65. North wind around 5 mph.
Tuesday
Mostly sunny, with a high near 82. North wind around 6 mph becoming light and variable.
Tuesday Night
Mostly cloudy, with a low around 65. Light and variable wind.
Wednesday
Partly sunny, with a high near 82. Calm wind becoming south 5 to 7 mph in the afternoon.
Wednesday Night
A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 71. South wind around 6 mph.
Thursday
Mostly sunny, with a high near 86.
Thursday Night
Partly cloudy, with a low around 73.
Friday
Mostly sunny, with a high near 88.
Friday Night
A chance of showers between 8pm and 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 30%.
Saturday
Mostly sunny, with a high near 86.
Saturday Night
A 30 percent chance of showers. Partly cloudy, with a low around 72.
Sunday
Mostly sunny, with a high near 87.
Sunday Night
Mostly clear, with a low around 72.
Monday
Sunny, with a high near 88.
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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:
2:53 am EDT Aug 4, 2026
Forecast Valid:
3am EDT Aug 4, 2026-6pm EDT Aug 10, 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