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

79°F

26°C

Humidity 67%
Wind Speed SE 13 mph
Barometer 30.16 in (1020.5 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index81°F (27°C)
Last update 11 Apr 12:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. Southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Chance
    T-storms

  • Tonight

    Tonight: A 50 percent chance of showers and thunderstorms, mainly after 10pm. Mostly cloudy, with a low around 68. Southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 68 °F

    Chance
    T-storms

  • Sunday

    Sunday: Showers and thunderstorms. High near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 77 °F

    T-storms

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 68. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Chance
    T-storms

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 84 °F

    Patchy Fog
    then Slight
    Chance
    T-storms

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 83 °F

    Cloudy then
    Slight Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 84 °F

    Cloudy then
    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. Southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A 50 percent chance of showers and thunderstorms, mainly after 10pm. Mostly cloudy, with a low around 68. Southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Sunday
Showers and thunderstorms. High near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Sunday Night
A 50 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 68. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Mostly cloudy, with a low around 67.
Thursday
Partly sunny, with a high near 88.
Thursday Night
Partly cloudy, with a low around 68.
Friday
Partly sunny, with a high near 89.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
12:44 pm CDT Apr 11, 2026
Forecast Valid:
1pm CDT Apr 11, 2026-6pm CDT Apr 17, 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