Dangerous Heat and Humidity Building from the Plains to the East Coast

A strengthening ridge of high pressure will produce much above average temperatures from the Plains to the East Coast, a true summer heat wave. Highs in the 90s and triple digits combined w/ humidity and dewpoints surging into the upper 70s, if not low 80s, will create heat indices as high as 110 to 115 through this weekend. Air quality will likely be poor due to haze and little air circulation. Read More >

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

82°F

28°C

Humidity 72%
Wind Speed S 10 mph
Barometer 30.01 in (1015.2 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 17 Jul 10:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Partly cloudy, with a low around 75. South wind 10 to 15 mph.

    Partly Cloudy

    Low: 75 °F

  • Thursday

    Thursday: Mostly cloudy, then gradually becoming sunny, with a high near 97. Heat index values as high as 104. South wind 10 to 15 mph.

    Decreasing
    Clouds

    High: 97 °F

  • Thursday
    Night

    Thursday Night: Increasing clouds, with a low around 75. South wind 10 to 15 mph, with gusts as high as 20 mph.

    Increasing
    Clouds

    Low: 75 °F

  • Friday

    Friday: Mostly sunny, with a high near 98. Heat index values as high as 105. South wind 10 to 15 mph.

    Mostly Sunny

    High: 98 °F

  • Friday
    Night

    Friday Night: Mostly clear, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Mostly Clear

    Low: 75 °F

  • Saturday

    Saturday: Mostly sunny, with a high near 97. South wind 10 to 15 mph.

    Mostly Sunny

    High: 97 °F

  • Saturday
    Night

    Saturday Night: Mostly clear, with a low around 74. South wind 10 to 15 mph, with gusts as high as 20 mph.

    Mostly Clear

    Low: 74 °F

  • Sunday

    Sunday: Sunny, with a high near 97. South wind around 10 mph.

    Sunny

    High: 97 °F

  • Sunday
    Night

    Sunday Night: Partly cloudy, with a low around 74. South wind 5 to 10 mph.

    Partly Cloudy

    Low: 74 °F

Detailed Forecast

Tonight
Partly cloudy, with a low around 75. South wind 10 to 15 mph.
Thursday
Mostly cloudy, then gradually becoming sunny, with a high near 97. Heat index values as high as 104. South wind 10 to 15 mph.
Thursday Night
Increasing clouds, with a low around 75. South wind 10 to 15 mph, with gusts as high as 20 mph.
Friday
Mostly sunny, with a high near 98. Heat index values as high as 105. South wind 10 to 15 mph.
Friday Night
Mostly clear, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Saturday
Mostly sunny, with a high near 97. South wind 10 to 15 mph.
Saturday Night
Mostly clear, with a low around 74. South wind 10 to 15 mph, with gusts as high as 20 mph.
Sunday
Sunny, with a high near 97. South wind around 10 mph.
Sunday Night
Partly cloudy, with a low around 74. South wind 5 to 10 mph.
Monday
Mostly sunny, with a high near 96.
Monday Night
Partly cloudy, with a low around 75.
Tuesday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 95.
Tuesday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73.
Wednesday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 93.
Click Map For Forecast
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
11:43 pm CDT Jul 17, 2019
11pm CDT Jul 17, 2019-6pm CDT Jul 24, 2019
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

National Digital Forecast Database