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 54%
Wind Speed SW 15 G 26 mph
Barometer 30.06 in (1017.3 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 3 Mar 10:56 am CST
Extended Forecast for

San Marcos TX

  • Today

    Today: Sunny, with a high near 87. South wind around 15 mph, with gusts as high as 25 mph.

    High: 87 °F

    Sunny

  • 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. Partly sunny, 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

Detailed Forecast

Today
Sunny, with a high near 87. South wind around 15 mph, with gusts as high as 25 mph.
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. Partly sunny, 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. 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.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
11:32 am CST Mar 3, 2026
Forecast Valid:
11am CST Mar 3, 2026-6pm CDT Mar 9, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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