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

83°F

28°C

Humidity 49%
Wind Speed SE 25 G 32 mph
Barometer 29.85 in (1010.1 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 5 Mar 3:56 pm CST
Extended Forecast for

San Marcos TX

  • 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

  • Monday Night

    Monday Night: A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

    Low: 68 °F

    Chance
    Showers

Detailed Forecast

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. South southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.
Tuesday
A chance of showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 81. Chance of precipitation is 50%.
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.
Wednesday Night
A 20 percent chance of showers. Mostly clear, with a low around 54.
Thursday
Sunny, with a high near 73.
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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:
4:32 pm CST Mar 5, 2026
Forecast Valid:
4pm CST Mar 5, 2026-6pm CDT Mar 12, 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