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

78°F

26°C

Humidity 69%
Wind Speed W 6 mph
Barometer 29.97 in (1014.2 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 7 Mar 12:56 pm CST
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Showers and possibly a thunderstorm before 3pm, then showers and thunderstorms likely after 3pm. High near 76. West wind around 15 mph becoming north. Winds could gust as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    High: 76 °F

    T-storms

  • Tonight

    Tonight: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 54. North wind 10 to 15 mph, with gusts as high as 25 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 54 °F

    Chance
    T-storms

  • Sunday

    Sunday: A 40 percent chance of showers and thunderstorms, mainly after 3pm. Mostly cloudy, with a high near 71. North wind 5 to 10 mph.

    High: 71 °F

    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 20 percent chance of showers and thunderstorms before midnight. Cloudy, with a low around 60. Northeast wind around 5 mph becoming calm.

    Low: 60 °F

    Slight Chance
    T-storms then
    Cloudy

  • Monday

    Monday: A slight chance of showers, then a chance of showers and thunderstorms after noon. Cloudy, with a high near 82. Light southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph. Chance of precipitation is 30%.

    High: 82 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A 20 percent chance of showers after midnight. Cloudy, with a low around 66. South southeast wind around 10 mph.

    Low: 66 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers before noon, then a chance of showers and thunderstorms between noon and 3pm, then a chance of showers after 3pm. 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

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 61. South southeast wind 15 to 20 mph decreasing to 5 to 10 mph after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 70%.

    Low: 61 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A 40 percent chance of showers, mainly before noon. Sunny, with a high near 84. Southwest wind 5 to 15 mph becoming north northwest in the afternoon. Winds could gust as high as 25 mph.

    High: 84 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Showers and possibly a thunderstorm before 3pm, then showers and thunderstorms likely after 3pm. High near 76. West wind around 15 mph becoming north. Winds could gust as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Tonight
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 54. North wind 10 to 15 mph, with gusts as high as 25 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
A 40 percent chance of showers and thunderstorms, mainly after 3pm. Mostly cloudy, with a high near 71. North wind 5 to 10 mph.
Sunday Night
A 20 percent chance of showers and thunderstorms before midnight. Cloudy, with a low around 60. Northeast wind around 5 mph becoming calm.
Monday
A slight chance of showers, then a chance of showers and thunderstorms after noon. Cloudy, with a high near 82. Light southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph. Chance of precipitation is 30%.
Monday Night
A 20 percent chance of showers after midnight. Cloudy, with a low around 66. South southeast wind around 10 mph.
Tuesday
A chance of showers before noon, then a chance of showers and thunderstorms between noon and 3pm, then a chance of showers after 3pm. Cloudy, with a high near 83. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.
Tuesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 61. South southeast wind 15 to 20 mph decreasing to 5 to 10 mph after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 70%.
Wednesday
A 40 percent chance of showers, mainly before noon. Sunny, with a high near 84. Southwest wind 5 to 15 mph becoming north northwest in the afternoon. Winds could gust as high as 25 mph.
Wednesday Night
A 20 percent chance of showers before midnight. Mostly clear, with a low around 51.
Thursday
Sunny, with a high near 71.
Thursday Night
Clear, with a low around 47.
Friday
Sunny, with a high near 79.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
1:10 pm CST Mar 7, 2026
Forecast Valid:
1pm CST Mar 7, 2026-6pm CDT Mar 13, 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