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

81°F

27°C

Humidity 69%
Wind Speed SE 8 mph
Barometer 29.89 in
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 22 Apr 6:56 pm CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Tonight

    Tonight: Mostly cloudy, with a low around 66. Southeast wind 5 to 10 mph.

    Low: 66 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 83. South wind 5 to 15 mph, with gusts as high as 20 mph.

    High: 83 °F

    Mostly Cloudy

  • Thursday Night

    Thursday 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

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 86. South southwest wind 5 to 10 mph.

    High: 86 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 69. South wind around 5 mph.

    Low: 69 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 89. South wind around 5 mph.

    High: 89 °F

    Mostly Cloudy

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 70. South southeast wind around 5 mph.

    Low: 70 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 91. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 91 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 71. South wind around 10 mph, with gusts as high as 20 mph.

    Low: 71 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Mostly cloudy, with a low around 66. Southeast wind 5 to 10 mph.
Thursday
Mostly cloudy, with a high near 83. South wind 5 to 15 mph, with gusts as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 86. South southwest wind 5 to 10 mph.
Friday Night
Mostly cloudy, with a low around 69. South wind around 5 mph.
Saturday
Mostly cloudy, with a high near 89. South wind around 5 mph.
Saturday Night
Partly cloudy, with a low around 70. South southeast wind around 5 mph.
Sunday
Mostly cloudy, with a high near 91. South wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday Night
Mostly cloudy, with a low around 71. South wind around 10 mph, with gusts as high as 20 mph.
Monday
Partly sunny, with a high near 92.
Monday Night
Partly cloudy, with a low around 68.
Tuesday
Partly sunny, with a high near 93.
Tuesday Night
Mostly cloudy, with a low around 69.
Wednesday
Partly sunny, with a high near 92.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos Municipal Airport TX
 29.88°N 97.86°W (Elev. 600 ft)
Last Update:
6:44 pm CDT Apr 22, 2026
Forecast Valid:
7pm CDT Apr 22, 2026-6pm CDT Apr 29, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation