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

73°F

23°C

Humidity 74%
Wind Speed S 15 mph
Barometer 30.06 in (1017.3 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 31 Mar 9:56 am CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 88. South wind around 15 mph, with gusts as high as 25 mph.

    High: 88 °F

    Partly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 66 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 91. South wind 10 to 20 mph, with gusts as high as 30 mph.

    High: 91 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms after 1am. Increasing clouds, with a low around 67. South southeast wind 15 to 20 mph decreasing to 10 to 15 mph after midnight. Winds could gust as high as 30 mph.

    Low: 67 °F

    Mostly 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 85. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.

    High: 85 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: A slight chance of thunderstorms before 7pm. Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 10%.

    Low: 68 °F

    Slight Chance
    T-storms then
    Mostly Cloudy

  • Friday

    Friday: Mostly cloudy, with a high near 88. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.

    High: 88 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: A slight chance of showers, with thunderstorms also possible after 1am. Mostly cloudy, with a low around 67. South southeast wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.

    Low: 67 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Saturday

    Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 81. South southeast wind 15 to 20 mph becoming east in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 60%.

    High: 81 °F

    Chance
    Showers then
    Showers
    Likely

Detailed Forecast

This Afternoon
Partly sunny, with a high near 88. South wind around 15 mph, with gusts as high as 25 mph.
Tonight
Increasing clouds, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 91. South wind 10 to 20 mph, with gusts as high as 30 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms after 1am. Increasing clouds, with a low around 67. South southeast wind 15 to 20 mph decreasing to 10 to 15 mph after midnight. Winds could gust as high as 30 mph.
Thursday
Showers likely and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 85. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
Thursday Night
A slight chance of thunderstorms before 7pm. Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 10%.
Friday
Mostly cloudy, with a high near 88. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.
Friday Night
A slight chance of showers, with thunderstorms also possible after 1am. Mostly cloudy, with a low around 67. South southeast wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 20%.
Saturday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 81. South southeast wind 15 to 20 mph becoming east in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 60%.
Saturday Night
A chance of showers and thunderstorms. Cloudy, with a low around 51. Chance of precipitation is 50%.
Sunday
A 40 percent chance of showers. Mostly cloudy, with a high near 67.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 47.
Monday
A 20 percent chance of showers. Mostly sunny, with a high near 70.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos Municipal Airport TX
 29.88°N 97.86°W (Elev. 600 ft)
Last Update:
12:46 pm CDT Mar 31, 2026
Forecast Valid:
12pm 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