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

70°F

21°C

Humidity 87%
Wind Speed E 5 mph
Barometer 30.08 in (1018.0 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 9 Apr 5:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm before 10pm, then a chance of showers and thunderstorms, mainly between 10pm and 1am. Mostly cloudy, with a low around 65. Southeast wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 65 °F

    Showers
    Likely then
    Chance
    Showers

  • Friday

    Friday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 80. Southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. Southeast wind 5 to 10 mph. Chance of precipitation is 30%.

    Low: 65 °F

    Chance
    Showers

  • Saturday

    Saturday: 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. Mostly cloudy, with a high near 81. Southeast wind 5 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.

    High: 81 °F

    Chance
    Showers then
    Showers
    Likely

  • Saturday Night

    Saturday Night: A 30 percent chance of showers and thunderstorms. Cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Sunday

    Sunday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 79. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%.

    High: 79 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: A 30 percent chance of showers and thunderstorms before 1am. Cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Chance
    T-storms

  • Monday

    Monday: Mostly cloudy, with a high near 82. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 82 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 68 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Showers likely and possibly a thunderstorm before 10pm, then a chance of showers and thunderstorms, mainly between 10pm and 1am. Mostly cloudy, with a low around 65. Southeast wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Friday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 80. Southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. Southeast wind 5 to 10 mph. Chance of precipitation is 30%.
Saturday
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. Mostly cloudy, with a high near 81. Southeast wind 5 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Saturday Night
A 30 percent chance of showers and thunderstorms. Cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Sunday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 79. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%.
Sunday Night
A 30 percent chance of showers and thunderstorms before 1am. Cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Monday
Mostly cloudy, with a high near 82. South wind 10 to 15 mph, with gusts as high as 25 mph.
Monday Night
Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84.
Tuesday Night
Mostly cloudy, with a low around 67.
Wednesday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 84.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Thursday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 84.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
Last Update:
5:36 pm CDT Apr 9, 2026
Forecast Valid:
6pm CDT Apr 9, 2026-6pm CDT Apr 16, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation