National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

91°F

33°C

Humidity 56%
Wind Speed SE 17 mph
Barometer 29.83 in (1009.1 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index100°F (38°C)
Last update 28 Jul 7:56 pm CDT
Extended Forecast for

5 Miles WNW San Marcos TX

  • Tonight

    Tonight: Increasing clouds, with a low around 75. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Mostly sunny, with a high near 97. Heat index values as high as 105. South wind 5 to 10 mph.

    High: 97 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Increasing clouds, with a low around 75. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Increasing
    Clouds

  • Thursday

    Thursday: Mostly sunny, with a high near 98. Heat index values as high as 104. South wind around 5 mph.

    High: 98 °F

    Mostly Sunny

  • Thursday Night

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

    Low: 74 °F

    Partly Cloudy

  • Friday

    Friday: Sunny, with a high near 98. South wind around 5 mph.

    High: 98 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 76. South wind around 5 mph.

    Low: 76 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny and hot, with a high near 100. South southwest wind around 5 mph.

    High: 100 °F

    Hot

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 77. South wind around 5 mph.

    Low: 77 °F

    Partly Cloudy

Detailed Forecast

Tonight
Increasing clouds, with a low around 75. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Wednesday
Mostly sunny, with a high near 97. Heat index values as high as 105. South wind 5 to 10 mph.
Wednesday Night
Increasing clouds, with a low around 75. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday
Mostly sunny, with a high near 98. Heat index values as high as 104. South wind around 5 mph.
Thursday Night
Partly cloudy, with a low around 74. South wind 5 to 10 mph.
Friday
Sunny, with a high near 98. South wind around 5 mph.
Friday Night
Mostly clear, with a low around 76. South wind around 5 mph.
Saturday
Mostly sunny and hot, with a high near 100. South southwest wind around 5 mph.
Saturday Night
Partly cloudy, with a low around 77. South wind around 5 mph.
Sunday
Mostly sunny, with a high near 98.
Sunday Night
Mostly clear, with a low around 76.
Monday
Sunny and hot, with a high near 99.
Monday Night
Mostly clear, with a low around 75.
Tuesday
Mostly sunny, with a high near 97.
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ABOUT THIS FORECAST

 
Point Forecast:
5 Miles WNW San Marcos TX
 29.9°N 97.99°W (Elev. 850 ft)
Last Update:
6:42 pm CDT Jul 28, 2026
Forecast Valid:
8pm CDT Jul 28, 2026-6pm CDT Aug 4, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation