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.

A Few Clouds

80°F

27°C

Humidity 38%
Wind Speed SE 7 mph
Barometer 30.06 in (1017.4 mb)
Dewpoint 52°F (11°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 8 Apr 2:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 80. South southeast wind around 5 mph.

    High: 80 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 61. Southeast wind around 5 mph becoming calm after midnight.

    Low: 61 °F

    Increasing
    Clouds

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms, mainly after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 83. Light east wind becoming east southeast 5 to 10 mph in the morning.

    High: 83 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 64. South southeast wind 5 to 10 mph. Chance of precipitation is 30%.

    Low: 64 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: 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. East southeast wind 5 to 10 mph. Chance of precipitation is 60%.

    High: 81 °F

    Chance
    Showers then
    Showers
    Likely

  • Friday Night

    Friday Night: A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 66. Southeast wind 5 to 10 mph. Chance of precipitation is 20%.

    Low: 66 °F

    Slight Chance
    T-storms then
    Slight Chance
    Showers

  • Saturday

    Saturday: A slight chance of showers, then a chance of showers and thunderstorms after 10am. Mostly cloudy, with a high near 82. Southeast wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.

    High: 82 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • 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 25 mph.

    Low: 67 °F

    Chance
    Showers

  • Sunday

    Sunday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 80. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.

    High: 80 °F

    Chance
    Showers then
    Showers
    Likely

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 80. South southeast wind around 5 mph.
Tonight
Increasing clouds, with a low around 61. Southeast wind around 5 mph becoming calm after midnight.
Thursday
A 30 percent chance of showers and thunderstorms, mainly after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 83. Light east wind becoming east southeast 5 to 10 mph in the morning.
Thursday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 64. South southeast wind 5 to 10 mph. Chance of precipitation is 30%.
Friday
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. East southeast wind 5 to 10 mph. Chance of precipitation is 60%.
Friday Night
A slight chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Mostly cloudy, with a low around 66. Southeast wind 5 to 10 mph. Chance of precipitation is 20%.
Saturday
A slight chance of showers, then a chance of showers and thunderstorms after 10am. Mostly cloudy, with a high near 82. Southeast wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.
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 25 mph.
Sunday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 80. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%.
Sunday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69.
Monday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 83.
Monday Night
Mostly cloudy, with a low around 69.
Tuesday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81.
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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 8, 2026
Forecast Valid:
3pm CDT Apr 8, 2026-6pm CDT Apr 14, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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