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.

Mostly Cloudy and Breezy

84°F

29°C

Humidity 55%
Wind Speed S 21 G 26 mph
Barometer 29.97 in (1014.1 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index86°F (30°C)
Last update 1 Apr 12:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 88. South wind around 15 mph, with gusts as high as 30 mph.

    High: 88 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 69. South wind 15 to 20 mph, with gusts as high as 30 mph.

    Low: 69 °F

    Increasing
    Clouds

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms, mainly before 1pm. Mostly cloudy, with a high near 82. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 82 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 69 °F

    Increasing
    Clouds

  • 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 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 70. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.

    Low: 70 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: Showers and possibly a thunderstorm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    High: 78 °F

    Showers

  • Saturday Night

    Saturday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 54. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 54 °F

    Chance
    T-storms

  • Sunday

    Sunday: A 30 percent chance of showers, mainly before 1pm. Cloudy, with a high near 66. North northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 66 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 88. South wind around 15 mph, with gusts as high as 30 mph.
Tonight
Increasing clouds, with a low around 69. South wind 15 to 20 mph, with gusts as high as 30 mph.
Thursday
A 40 percent chance of showers and thunderstorms, mainly before 1pm. Mostly cloudy, with a high near 82. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Thursday Night
Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 25 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 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 70. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.
Saturday
Showers and possibly a thunderstorm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Saturday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 54. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday
A 30 percent chance of showers, mainly before 1pm. Cloudy, with a high near 66. North northeast wind around 15 mph, with gusts as high as 25 mph.
Sunday Night
Cloudy, with a low around 52.
Monday
Mostly cloudy, with a high near 70.
Monday Night
Partly cloudy, with a low around 51.
Tuesday
Mostly cloudy, with a high near 72.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
1:24 pm CDT Apr 1, 2026
Forecast Valid:
1pm CDT Apr 1, 2026-6pm CDT Apr 7, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation