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.

A Few Clouds

97°F

36°C

Humidity 39%
Wind Speed SE 13 mph
Barometer 30.09 in (1018.1 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 7 Aug 2:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Sunny, with a high near 97. Heat index values as high as 103. South wind around 5 mph.

    High: 97 °F

    Sunny

  • Tonight

    Tonight: Clear, with a low around 75. South southeast wind around 5 mph.

    Low: 75 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 98. Heat index values as high as 103. Calm wind becoming south around 5 mph in the afternoon.

    High: 98 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 74. Southeast wind around 5 mph.

    Low: 74 °F

    Clear

  • Saturday

    Saturday: Sunny, with a high near 97. Calm wind becoming east southeast around 5 mph in the afternoon.

    High: 97 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 73. Southeast wind 5 to 10 mph becoming light south after midnight.

    Low: 73 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 95. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 95 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 74. Southeast wind 5 to 10 mph becoming light south after midnight.

    Low: 74 °F

    Mostly Clear

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 95. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 95 °F

    Sunny then
    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
Sunny, with a high near 97. Heat index values as high as 103. South wind around 5 mph.
Tonight
Clear, with a low around 75. South southeast wind around 5 mph.
Friday
Sunny, with a high near 98. Heat index values as high as 103. Calm wind becoming south around 5 mph in the afternoon.
Friday Night
Clear, with a low around 74. Southeast wind around 5 mph.
Saturday
Sunny, with a high near 97. Calm wind becoming east southeast around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 73. Southeast wind 5 to 10 mph becoming light south after midnight.
Sunday
Sunny, with a high near 95. Calm wind becoming southeast around 5 mph in the afternoon.
Sunday Night
Mostly clear, with a low around 74. Southeast wind 5 to 10 mph becoming light south after midnight.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 95. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
Mostly clear, with a low around 74.
Tuesday
Sunny, with a high near 96.
Tuesday Night
Mostly clear, with a low around 74.
Wednesday
Sunny, with a high near 96.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
1:44 pm CDT Aug 7, 2025
Forecast Valid:
3pm CDT Aug 7, 2025-6pm CDT Aug 13, 2025
 
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