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.

Fair

96°F

36°C

Humidity 41%
Wind Speed S 12 mph
Barometer 30.04 in (1016.2 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index101°F (38°C)
Last update 7 Jul 3:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 95. South wind around 5 mph.

    High: 95 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 10pm. Partly cloudy, with a low around 74. South wind around 5 mph. Chance of precipitation is 20%.

    Low: 74 °F

    Slight Chance
    T-storms then
    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 96. Heat index values as high as 100. South wind 5 to 10 mph.

    High: 96 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 73. South wind 5 to 10 mph.

    Low: 73 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 96. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 96 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 75. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 75 °F

    Mostly Clear

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 94 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Friday Night

    Friday Night: Partly cloudy, with a low around 76. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 76 °F

    Partly Cloudy

  • Saturday

    Saturday: A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 93. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 93 °F

    Partly Sunny
    then Chance
    T-storms

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 95. South wind around 5 mph.
Tonight
A slight chance of showers and thunderstorms before 7pm, then a slight chance of showers between 7pm and 10pm. Partly cloudy, with a low around 74. South wind around 5 mph. Chance of precipitation is 20%.
Wednesday
Mostly sunny, with a high near 96. Heat index values as high as 100. South wind 5 to 10 mph.
Wednesday Night
Mostly clear, with a low around 73. South wind 5 to 10 mph.
Thursday
Sunny, with a high near 96. South wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Mostly clear, with a low around 75. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
Partly cloudy, with a low around 76. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday
A 40 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 93. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday Night
Partly cloudy, with a low around 76.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 93.
Sunday Night
A 20 percent chance of showers. Partly cloudy, with a low around 76.
Monday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 94.
Monday Night
Partly cloudy, with a low around 76.
Tuesday
Mostly sunny, with a high near 95.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
3:44 pm CDT Jul 7, 2026
Forecast Valid:
4pm CDT Jul 7, 2026-6pm CDT Jul 14, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation