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 with Haze

76°F

24°C

Humidity 74%
Wind Speed NE 10 mph
Barometer 29.86 in (1010.4 mb)
Dewpoint 67°F (19°C)
Visibility 5.00 mi
Heat Index77°F (25°C)
Last update 6 May 12:56 pm CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms before 4pm. Mostly cloudy, with a high near 78. North wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 78 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: Mostly cloudy, with a low around 63. North northeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 63 °F

    Mostly Cloudy

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 4pm. Cloudy, with a high near 74. North wind around 15 mph, with gusts as high as 25 mph.

    High: 74 °F

    Cloudy then
    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 64. East northeast wind 5 to 10 mph. Chance of precipitation is 20%.

    Low: 64 °F

    Slight Chance
    T-storms

  • Friday

    Friday: A chance of showers, with thunderstorms also possible after 10am. Mostly cloudy, with a high near 79. Northeast wind 5 to 10 mph becoming southeast in the afternoon. Chance of precipitation is 50%.

    High: 79 °F

    Chance
    Showers then
    Chance
    T-storms

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Southeast wind 5 to 10 mph.

    Low: 68 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers and thunderstorms likely, mainly after 1pm. Mostly cloudy, with a high near 83. East wind 5 to 10 mph becoming south in the afternoon. Chance of precipitation is 60%.

    High: 83 °F

    T-storms
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 68. East southeast wind around 5 mph becoming calm in the evening.

    Low: 68 °F

    Chance
    T-storms

  • Sunday

    Sunday: Mostly sunny, with a high near 88. Calm wind becoming east northeast around 5 mph in the afternoon.

    High: 88 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms before 4pm. Mostly cloudy, with a high near 78. North wind 10 to 15 mph, with gusts as high as 20 mph.
Tonight
Mostly cloudy, with a low around 63. North northeast wind 10 to 15 mph, with gusts as high as 20 mph.
Thursday
A 20 percent chance of showers and thunderstorms after 4pm. Cloudy, with a high near 74. North wind around 15 mph, with gusts as high as 25 mph.
Thursday Night
A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 64. East northeast wind 5 to 10 mph. Chance of precipitation is 20%.
Friday
A chance of showers, with thunderstorms also possible after 10am. Mostly cloudy, with a high near 79. Northeast wind 5 to 10 mph becoming southeast in the afternoon. Chance of precipitation is 50%.
Friday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Southeast wind 5 to 10 mph.
Saturday
Showers and thunderstorms likely, mainly after 1pm. Mostly cloudy, with a high near 83. East wind 5 to 10 mph becoming south in the afternoon. Chance of precipitation is 60%.
Saturday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Partly cloudy, with a low around 68. East southeast wind around 5 mph becoming calm in the evening.
Sunday
Mostly sunny, with a high near 88. Calm wind becoming east northeast around 5 mph in the afternoon.
Sunday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 67.
Monday
Sunny, with a high near 84.
Monday Night
Mostly clear, with a low around 62.
Tuesday
Mostly sunny, with a high near 86.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos Municipal Airport TX
 29.9°N 97.86°W (Elev. 600 ft)
Last Update:
1:24 pm CDT May 6, 2026
Forecast Valid:
1pm CDT May 6, 2026-6pm CDT May 12, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation