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

76°F

24°C

Humidity 77%
Wind Speed S 20 mph
Barometer 29.97 in (1014.3 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 5 Mar 9:56 am CST
Extended Forecast for

San Marcos TX

  • Today

    Today: A 20 percent chance of showers before 3pm. Cloudy, then gradually becoming mostly sunny, with a high near 86. South wind 15 to 20 mph, with gusts as high as 30 mph.

    High: 86 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: A 20 percent chance of showers after 3am. 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
    Showers

  • Friday

    Friday: A slight chance of showers, 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 20%.

    High: 84 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A slight chance of showers and thunderstorms, then a chance of showers 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 30%.

    Low: 67 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: Showers, with thunderstorms also possible after 3pm. High near 83. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.

    High: 83 °F

    Showers

  • Saturday Night

    Saturday Night: Showers and possibly a thunderstorm. Low around 57. East wind around 10 mph becoming north after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 80%.

    Low: 57 °F

    T-storms

  • Sunday

    Sunday: Showers and possibly a thunderstorm. High near 71. North northeast wind 5 to 10 mph. Chance of precipitation is 80%.

    High: 71 °F

    Showers

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 61. Northeast wind around 5 mph becoming calm in the evening.

    Low: 61 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday

    Monday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after noon. Cloudy, with a high near 82. East wind 5 to 15 mph becoming south in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 70%.

    High: 82 °F

    Chance
    T-storms then
    Showers
    Likely

Detailed Forecast

Today
A 20 percent chance of showers before 3pm. Cloudy, then gradually becoming mostly sunny, with a high near 86. South wind 15 to 20 mph, with gusts as high as 30 mph.
Tonight
A 20 percent chance of showers after 3am. Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday
A slight chance of showers, 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 20%.
Friday Night
A slight chance of showers and thunderstorms, then a chance of showers 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 30%.
Saturday
Showers, with thunderstorms also possible after 3pm. High near 83. 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 57. East wind around 10 mph becoming north after midnight. Winds could gust as high as 20 mph. Chance of precipitation is 80%.
Sunday
Showers and possibly a thunderstorm. High near 71. 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 61. Northeast wind around 5 mph becoming calm in the evening.
Monday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after noon. Cloudy, with a high near 82. East wind 5 to 15 mph becoming south in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 70%.
Monday Night
A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 65.
Tuesday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 80. Chance of precipitation is 60%.
Tuesday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 58.
Wednesday
A 20 percent chance of showers. Mostly sunny, with a high near 77.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
6:44 am CST Mar 5, 2026
Forecast Valid:
10am CST Mar 5, 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