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

79°F

26°C

Humidity 60%
Wind Speed SE 20 mph
Barometer 29.95 in (1013.5 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index81°F (27°C)
Last update 3 Mar 6:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: A slight chance of drizzle after midnight. Increasing clouds, with a low around 68. South wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 68 °F

    Partly Cloudy
    then Slight
    Chance
    Drizzle

  • Wednesday

    Wednesday: A slight chance of drizzle before 9am, then a slight chance of showers between 9am and noon, then a chance of showers and thunderstorms after noon. Cloudy, then gradually becoming mostly sunny, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 84 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms. Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 66 °F

    Chance
    Showers

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms before noon. Cloudy through mid morning, then gradual clearing, with a high near 85. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 85 °F

    Chance
    Showers then
    Mostly Sunny

  • Thursday Night

    Thursday Night: A 30 percent chance of showers after midnight. Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 67 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: A chance of showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 85. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 50%.

    High: 85 °F

    Chance
    Showers then
    Chance
    T-storms

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm before midnight, then a chance of showers and thunderstorms after midnight. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.

    Low: 67 °F

    Showers
    Likely

  • Saturday

    Saturday: A chance of showers, then showers and possibly a thunderstorm after noon. High near 84. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.

    High: 84 °F

    Chance
    Showers then
    Showers

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm. Cloudy, with a low around 64. East wind 5 to 10 mph. Chance of precipitation is 70%.

    Low: 64 °F

    Showers
    Likely

Detailed Forecast

Tonight
A slight chance of drizzle after midnight. Increasing clouds, with a low around 68. South wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
A slight chance of drizzle before 9am, then a slight chance of showers between 9am and noon, then a chance of showers and thunderstorms after noon. Cloudy, then gradually becoming mostly sunny, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
A 30 percent chance of showers and thunderstorms. Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Thursday
A 30 percent chance of showers and thunderstorms before noon. Cloudy through mid morning, then gradual clearing, with a high near 85. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Thursday Night
A 30 percent chance of showers after midnight. Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday
A chance of showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 85. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 50%.
Friday Night
Showers likely and possibly a thunderstorm before midnight, then a chance of showers and thunderstorms after midnight. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Saturday
A chance of showers, then showers and possibly a thunderstorm after noon. High near 84. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.
Saturday Night
Showers likely and possibly a thunderstorm. Cloudy, with a low around 64. East wind 5 to 10 mph. Chance of precipitation is 70%.
Sunday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 78. Chance of precipitation is 70%.
Sunday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 63.
Monday
A 40 percent chance of showers. Mostly cloudy, with a high near 82.
Monday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 64.
Tuesday
A 30 percent chance of showers. Mostly cloudy, with a high near 82.
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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:
5:44 pm CST Mar 3, 2026
Forecast Valid:
7pm CST Mar 3, 2026-6pm CDT Mar 10, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation