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.

Overcast

71°F

22°C

Humidity 81%
Wind Speed S 15 mph
Barometer 30.01 in (1015.4 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Last update 4 Mar 10:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Cloudy, with a low around 67. South wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 67 °F

    Cloudy

  • Thursday

    Thursday: A chance of showers and thunderstorms before 9am, then a slight chance of showers between 9am and 3pm. Cloudy, then gradually becoming mostly sunny, with a high near 85. South southeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 30%.

    High: 85 °F

    Chance
    Showers

  • Thursday Night

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

    Low: 66 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Friday

    Friday: Showers likely, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 84. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.

    High: 84 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: Showers likely, 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

    Showers

  • Saturday Night

    Saturday Night: Showers and possibly a thunderstorm. Low around 59. North northeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.

    Low: 59 °F

    Showers

  • Sunday

    Sunday: Showers, with thunderstorms also possible after noon. High near 73. Northeast wind 5 to 10 mph. Chance of precipitation is 80%.

    High: 73 °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 east southeast after midnight.

    Low: 63 °F

    Chance
    Showers

Detailed Forecast

Tonight
Cloudy, with a low around 67. South wind 10 to 15 mph, with gusts as high as 25 mph.
Thursday
A chance of showers and thunderstorms before 9am, then a slight chance of showers between 9am and 3pm. Cloudy, then gradually becoming mostly sunny, with a high near 85. South southeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 30%.
Thursday Night
A 20 percent chance of showers and thunderstorms after midnight. Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday
Showers likely, with thunderstorms also possible after 3pm. Mostly cloudy, with a high near 84. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.
Friday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday
Showers likely, 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 and possibly a thunderstorm. Low around 59. North northeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.
Sunday
Showers, with thunderstorms also possible after noon. High near 73. 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 east southeast after midnight.
Monday
A 50 percent chance of showers. Mostly cloudy, with a high near 83.
Monday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Tuesday
Showers likely. Mostly cloudy, with a high near 81. Chance of precipitation is 60%.
Tuesday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57.
Wednesday
A 20 percent chance of showers. Sunny, with a high near 78.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
10:32 pm CST Mar 4, 2026
Forecast Valid:
11pm CST Mar 4, 2026-6pm CDT Mar 11, 2026
 
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