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

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

85°F

29°C

Humidity 65%
Wind Speed S 12 mph
Barometer 29.99 in (1014.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index91°F (33°C)
Last update 19 Aug 10:56 pm CDT
Extended Forecast for

2 Miles E San Marcos TX

Heat Advisory August 20, 02:00pm until August 23, 07:00pm
Click here for hazard details and duration
Heat Advisory

  • Tonight

    Tonight: Partly cloudy, with a low around 77. South wind 5 to 10 mph.

    Low: 77 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny and hot, with a high near 102. Heat index values as high as 107. South southwest wind around 5 mph.

    High: 102 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 77. South wind 5 to 10 mph.

    Low: 77 °F

    Mostly Clear

  • Friday

    Friday: Mostly sunny and hot, with a high near 102. Heat index values as high as 107. South southwest wind around 5 mph.

    High: 102 °F

    Hot

  • Friday Night

    Friday Night: Partly cloudy, with a low around 78. South southeast wind around 5 mph.

    Low: 78 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny and hot, with a high near 103. Southwest wind around 5 mph becoming south southeast in the afternoon.

    High: 103 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 78. South southeast wind around 5 mph.

    Low: 78 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 103. Southwest wind around 5 mph becoming south southeast in the afternoon.

    High: 103 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 78. South southeast wind 5 to 10 mph.

    Low: 78 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 77. South wind 5 to 10 mph.
Thursday
Mostly sunny and hot, with a high near 102. Heat index values as high as 107. South southwest wind around 5 mph.
Thursday Night
Mostly clear, with a low around 77. South wind 5 to 10 mph.
Friday
Mostly sunny and hot, with a high near 102. Heat index values as high as 107. South southwest wind around 5 mph.
Friday Night
Partly cloudy, with a low around 78. South southeast wind around 5 mph.
Saturday
Sunny and hot, with a high near 103. Southwest wind around 5 mph becoming south southeast in the afternoon.
Saturday Night
Mostly clear, with a low around 78. South southeast wind around 5 mph.
Sunday
Sunny and hot, with a high near 103. Southwest wind around 5 mph becoming south southeast in the afternoon.
Sunday Night
Mostly clear, with a low around 78. South southeast wind 5 to 10 mph.
Monday
Sunny and hot, with a high near 102.
Monday Night
Mostly clear, with a low around 77.
Tuesday
Sunny and hot, with a high near 101.
Tuesday Night
Mostly clear, with a low around 77.
Wednesday
Sunny and hot, with a high near 101.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles E San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
11:32 pm CDT Aug 19, 2026
Forecast Valid:
11pm CDT Aug 19, 2026-6pm CDT Aug 26, 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

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Chance of Precipitation