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

76°F

24°C

Humidity 82%
Wind Speed SE 13 mph
Barometer 29.79 in (1008.0 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 23 Apr 8:56 pm CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Tonight

    Tonight: Mostly cloudy, with a low around 70. South southeast wind around 10 mph.

    Low: 70 °F

    Mostly Cloudy

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 85. South wind 5 to 10 mph.

    High: 85 °F

    Cloudy then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: A 20 percent chance of showers and thunderstorms before 10pm. Mostly cloudy, with a low around 69. South wind around 5 mph.

    Low: 69 °F

    Slight Chance
    T-storms then
    Mostly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 89. South wind 5 to 10 mph.

    High: 89 °F

    Mostly Cloudy

  • Saturday Night

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

    Low: 70 °F

    Mostly 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 southeast wind around 10 mph.

    Low: 71 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 93. South southwest wind around 5 mph.

    High: 93 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. South southeast wind around 5 mph.

    Low: 70 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
Mostly cloudy, with a low around 70. South southeast wind around 10 mph.
Friday
A 20 percent chance of showers and thunderstorms after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 85. South wind 5 to 10 mph.
Friday Night
A 20 percent chance of showers and thunderstorms before 10pm. Mostly cloudy, with a low around 69. South wind around 5 mph.
Saturday
Mostly cloudy, with a high near 89. South wind 5 to 10 mph.
Saturday Night
Mostly cloudy, with a low around 70. South 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 southeast wind around 10 mph.
Monday
Mostly cloudy, with a high near 93. South southwest wind around 5 mph.
Monday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. South southeast wind around 5 mph.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 94.
Tuesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70.
Wednesday
Mostly cloudy, with a high near 92.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 89.
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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:
6:44 pm CDT Apr 23, 2026
Forecast Valid:
9pm CDT Apr 23, 2026-6pm CDT Apr 30, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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