Dangerous heat and humidity from the central U.S. to East Coast this weekend

Hot and very humid conditions will push the heat index to well over 100 degrees across a large portion of the central and eastern U.S. Excessive Heat Warnings and Heat Advisories are in effect for much of the Plains, Miss. Valley, Midwest, Ohio Valley, Mid-Atlantic and southern states. Be very cautious if you must do outdoor activities in these areas during the afternoon and evening this weekend. Read More >

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

82°F

28°C

Humidity 53%
Wind Speed SW 9 mph
Barometer 29.95 in (1014.1 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 24 Jul 5:56 pm EDT
Extended Forecast for

Holtsville NY

Heat Advisory July 25, 12:00pm until July 25, 08:00pm
Click here for hazard details and duration
Heat Advisory
  • Tonight

    Tonight: Increasing clouds, with a low around 73. South wind 6 to 9 mph.

    Increasing
    Clouds

    Low: 73 °F

  • Monday

    Monday: A 40 percent chance of showers and thunderstorms, mainly after 8am. Some of the storms could produce gusty winds and heavy rain.  Mostly cloudy, with a high near 88. Heat index values as high as 97. Southwest wind 7 to 10 mph.

    Heavy Rain

    High: 88 °F

  • Monday
    Night

    Monday Night: A 40 percent chance of showers and thunderstorms, mainly before midnight.  Mostly cloudy, with a low around 74. Southwest wind 6 to 8 mph.

    Chance
    T-storms

    Low: 74 °F

  • Tuesday

    Tuesday: Sunny, with a high near 90. North wind 7 to 11 mph becoming west in the afternoon.

    Sunny

    High: 90 °F

  • Tuesday
    Night

    Tuesday Night: Mostly clear, with a low around 68. Light and variable wind becoming north around 6 mph in the evening.

    Mostly Clear

    Low: 68 °F

  • Wednesday

    Wednesday: Sunny, with a high near 88.

    Sunny

    High: 88 °F

  • Wednesday
    Night

    Wednesday Night: Partly cloudy, with a low around 70.

    Partly Cloudy

    Low: 70 °F

  • Thursday

    Thursday: Partly sunny, with a high near 87.

    Partly Sunny

    High: 87 °F

  • Thursday
    Night

    Thursday Night: Mostly cloudy, with a low around 71.

    Mostly Cloudy

    Low: 71 °F

Detailed Forecast

Tonight
Increasing clouds, with a low around 73. South wind 6 to 9 mph.
Monday
A 40 percent chance of showers and thunderstorms, mainly after 8am. Some of the storms could produce gusty winds and heavy rain. Mostly cloudy, with a high near 88. Heat index values as high as 97. Southwest wind 7 to 10 mph.
Monday Night
A 40 percent chance of showers and thunderstorms, mainly before midnight. Mostly cloudy, with a low around 74. Southwest wind 6 to 8 mph.
Tuesday
Sunny, with a high near 90. North wind 7 to 11 mph becoming west in the afternoon.
Tuesday Night
Mostly clear, with a low around 68. Light and variable wind becoming north around 6 mph in the evening.
Wednesday
Sunny, with a high near 88.
Wednesday Night
Partly cloudy, with a low around 70.
Thursday
Partly sunny, with a high near 87.
Thursday Night
Mostly cloudy, with a low around 71.
Friday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 87.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71.
Saturday
Partly sunny, with a high near 86.
Saturday Night
Mostly cloudy, with a low around 70.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 84.
Click Map For Forecast
Point Forecast:
Holtsville NY
 40.82°N 73.05°W (Elev. 112 ft)
6:15 pm EDT Jul 24, 2016
6pm EDT Jul 24, 2016-6pm EDT Jul 31, 2016
 
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Additional Resources

Radar & Satellite Image

Northeast Radar Mosaic Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database