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.

Mostly Cloudy and Breezy

86°F

30°C

Humidity 45%
Wind Speed S 22 G 33 mph
Barometer 29.87 in (1010.5 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 5 Mar 2:56 pm CST
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 85. South southeast wind 15 to 20 mph, with gusts as high as 30 mph.

    High: 85 °F

    Mostly Sunny

  • Tonight

    Tonight: A 20 percent chance of showers and thunderstorms after 3am. Increasing clouds, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 68 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Friday

    Friday: A chance of showers, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 83. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.

    High: 83 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms. Increasing clouds, with a low around 68. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Chance
    T-storms

  • Saturday

    Saturday: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after noon. High near 82. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.

    High: 82 °F

    Chance
    Showers then
    Showers

  • Saturday Night

    Saturday Night: Showers and possibly a thunderstorm. Low around 59. East wind around 10 mph becoming north after midnight. Chance of precipitation is 90%.

    Low: 59 °F

    T-storms then
    Showers

  • Sunday

    Sunday: Showers and possibly a thunderstorm. High near 70. North northeast wind 5 to 10 mph. Chance of precipitation is 80%.

    High: 70 °F

    Showers

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 63. Northeast wind around 5 mph becoming calm.

    Low: 63 °F

    Chance
    T-storms

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 82 °F

    Chance
    Showers then
    Chance
    T-storms

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 85. South southeast wind 15 to 20 mph, with gusts as high as 30 mph.
Tonight
A 20 percent chance of showers and thunderstorms after 3am. Increasing clouds, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday
A chance of showers, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 83. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.
Friday Night
A 40 percent chance of showers and thunderstorms. Increasing clouds, with a low around 68. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Saturday
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after noon. High near 82. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.
Saturday Night
Showers and possibly a thunderstorm. Low around 59. East wind around 10 mph becoming north after midnight. Chance of precipitation is 90%.
Sunday
Showers and possibly a thunderstorm. High near 70. North northeast wind 5 to 10 mph. Chance of precipitation is 80%.
Sunday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 63. Northeast wind around 5 mph becoming calm.
Monday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82. South wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 68. Chance of precipitation is 30%.
Tuesday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81.
Tuesday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 62.
Wednesday
A 30 percent chance of showers. Mostly sunny, with a high near 80.
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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 CST Mar 5, 2026
Forecast Valid:
3pm CST Mar 5, 2026-6pm CDT Mar 11, 2026
 
Forecast Discussion
 
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Additional Resources

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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