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

78°F

26°C

Humidity 71%
Wind Speed NE 8 mph
Barometer 30.11 in (1019.1 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 10 Apr 3:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 81. East southeast wind around 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 81 °F

    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 66. East southeast wind 5 to 10 mph. Chance of precipitation is 30%.

    Low: 66 °F

    Chance
    T-storms then
    Slight Chance
    Showers

  • Saturday

    Saturday: A slight chance of showers, then a chance of showers and thunderstorms after 10am. Patchy fog between 8am and 11am. Otherwise, mostly cloudy, with a high near 81. East southeast wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 81 °F

    Chance
    Showers and
    Patchy Fog
    then Chance
    T-storms

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 40%.

    Low: 68 °F

    Chance
    Showers and
    Patchy Fog

  • Sunday

    Sunday: A chance of showers before 10am, then a chance of showers and thunderstorms between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. Patchy fog before 11am. Otherwise, cloudy, with a high near 78. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.

    High: 78 °F

    Showers
    Likely and
    Patchy Fog

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms before 1am. Patchy fog between 10pm and 3am. Otherwise, cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Chance
    T-storms and
    Patchy Fog

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 82. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 82 °F

    Patchy Fog
    then Slight
    Chance
    T-storms

  • Monday Night

    Monday Night: A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    Low: 69 °F

    Slight Chance
    T-storms

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 83 °F

    Slight Chance
    T-storms

Detailed Forecast

This Afternoon
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 81. East southeast wind around 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 66. East southeast wind 5 to 10 mph. Chance of precipitation is 30%.
Saturday
A slight chance of showers, then a chance of showers and thunderstorms after 10am. Patchy fog between 8am and 11am. Otherwise, mostly cloudy, with a high near 81. East southeast wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 40%.
Sunday
A chance of showers before 10am, then a chance of showers and thunderstorms between 10am and 1pm, then showers likely and possibly a thunderstorm after 1pm. Patchy fog before 11am. Otherwise, cloudy, with a high near 78. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
Sunday Night
A 50 percent chance of showers and thunderstorms before 1am. Patchy fog between 10pm and 3am. Otherwise, cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 82. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Monday Night
A slight chance of showers and thunderstorms. Mostly cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Tuesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 67.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 85.
Wednesday Night
Mostly cloudy, with a low around 68.
Thursday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 83.
Thursday Night
Mostly cloudy, with a low around 68.
Friday
Partly sunny, with a high near 87.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
2:46 pm CDT Apr 10, 2026
Forecast Valid:
4pm CDT Apr 10, 2026-6pm CDT Apr 17, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation