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.

Partly Cloudy

88°F

31°C

Humidity 39%
Wind Speed S 16 G 22 mph
Barometer 29.96 in (1013.6 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Heat Index88°F (31°C)
Last update 31 Mar 2:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 87. South southeast wind around 15 mph, with gusts as high as 25 mph.

    High: 87 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 67. South wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 67 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 89. South wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 89 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: A slight chance of showers between 1am and 4am, then a slight chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 68. South southeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.

    Low: 68 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 83. South southeast wind 5 to 10 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.

    High: 83 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Slight Chance
    T-storms

  • Friday

    Friday: Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 87 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: A 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 67 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 77. South southeast wind 10 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 70%.

    High: 77 °F

    Showers
    Likely

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 87. South southeast wind around 15 mph, with gusts as high as 25 mph.
Tonight
Increasing clouds, with a low around 67. South wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 89. South wind 10 to 15 mph, with gusts as high as 30 mph.
Wednesday Night
A slight chance of showers between 1am and 4am, then a slight chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 68. South southeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.
Thursday
Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 83. South southeast wind 5 to 10 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
Thursday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Friday
Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday Night
A 30 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Saturday
Showers likely and possibly a thunderstorm. Cloudy, with a high near 77. South southeast wind 10 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 70%.
Saturday Night
A 50 percent chance of showers. Cloudy, with a low around 53.
Sunday
A 30 percent chance of showers. Cloudy, with a high near 65.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 49.
Monday
Partly sunny, with a high near 69.
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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:
2:46 pm CDT Mar 31, 2026
Forecast Valid:
3pm CDT Mar 31, 2026-6pm CDT Apr 6, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation