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

70°F

21°C

Humidity 100%
Wind Speed S 5 mph
Barometer 30.00 in (1015.3 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 16 Jun 6:56 am CDT
Extended Forecast for

San Marcos TX

  • Today

    Today: A slight chance of showers and thunderstorms before 10am, then a slight chance of showers and thunderstorms after 4pm. Mostly cloudy, then gradually becoming sunny, with a high near 94. Heat index values as high as 103. South southwest wind 5 to 10 mph. Chance of precipitation is 20%.

    High: 94 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A 10 percent chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 73. South wind 5 to 10 mph.

    Low: 73 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 95. Heat index values as high as 103. South wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 95 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 75 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 95. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 95 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 75. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 75 °F

    Partly Cloudy

  • Juneteenth

    Juneteenth: A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. South southeast wind 5 to 10 mph.

    High: 92 °F

    Partly Sunny
    then Chance
    T-storms

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 73. South southeast wind 5 to 10 mph.

    Low: 73 °F

    Partly Cloudy

  • Friday

    Friday: A 30 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 90. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 90 °F

    Chance
    T-storms

Detailed Forecast

Today
A slight chance of showers and thunderstorms before 10am, then a slight chance of showers and thunderstorms after 4pm. Mostly cloudy, then gradually becoming sunny, with a high near 94. Heat index values as high as 103. South southwest wind 5 to 10 mph. Chance of precipitation is 20%.
Tonight
A 10 percent chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 73. South wind 5 to 10 mph.
Tuesday
Sunny, with a high near 95. Heat index values as high as 103. South wind 5 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly clear, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
Mostly sunny, with a high near 95. South wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 75. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Juneteenth
A 30 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. South southeast wind 5 to 10 mph.
Thursday Night
Partly cloudy, with a low around 73. South southeast wind 5 to 10 mph.
Friday
A 30 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 90. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
Mostly cloudy, with a low around 72.
Saturday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 91.
Saturday Night
Partly cloudy, with a low around 72.
Sunday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 89.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
6:42 am CDT Jun 16, 2025
Forecast Valid:
7am CDT Jun 16, 2025-6pm CDT Jun 22, 2025
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation