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.

Overcast

71°F

22°C

Humidity 84%
Wind Speed S 8 mph
Barometer 29.93 in (1012.8 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 6 Mar 12:56 am CST
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Cloudy, with a low around 68. South wind around 15 mph, with gusts as high as 25 mph.

    Low: 68 °F

    Cloudy

  • Friday

    Friday: A slight chance of showers, then a chance of showers and thunderstorms after noon. Mostly cloudy, with a high near 82. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.

    High: 82 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 20 percent chance of showers before 9pm. Mostly cloudy, with a low around 69. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Slight Chance
    Showers then
    Cloudy

  • Saturday

    Saturday: A chance of showers, then showers and possibly a thunderstorm after noon. High near 83. South southeast wind 5 to 10 mph becoming east northeast in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 90%.

    High: 83 °F

    Chance
    Showers then
    Showers

  • Saturday Night

    Saturday Night: Showers and possibly a thunderstorm. Low around 57. North northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.

    Low: 57 °F

    T-storms then
    Showers

  • Sunday

    Sunday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 66. North northeast wind 5 to 10 mph. Chance of precipitation is 70%.

    High: 66 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 62. North northeast wind around 5 mph becoming southeast after midnight.

    Low: 62 °F

    Chance
    T-storms

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 30 percent chance of showers and thunderstorms after midnight. Mostly cloudy, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Mostly Cloudy
    then Chance
    T-storms

Detailed Forecast

Overnight
Cloudy, with a low around 68. South wind around 15 mph, with gusts as high as 25 mph.
Friday
A slight chance of showers, then a chance of showers and thunderstorms after noon. Mostly cloudy, with a high near 82. South wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.
Friday Night
A 20 percent chance of showers before 9pm. Mostly cloudy, with a low around 69. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Saturday
A chance of showers, then showers and possibly a thunderstorm after noon. High near 83. South southeast wind 5 to 10 mph becoming east northeast in the afternoon. Winds could gust as high as 20 mph. Chance of precipitation is 90%.
Saturday Night
Showers and possibly a thunderstorm. Low around 57. North northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 80%.
Sunday
Showers likely and possibly a thunderstorm. Cloudy, with a high near 66. North northeast wind 5 to 10 mph. Chance of precipitation is 70%.
Sunday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 62. North northeast wind around 5 mph becoming southeast after midnight.
Monday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81. South wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
A 30 percent chance of showers and thunderstorms after midnight. Mostly cloudy, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.
Tuesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after noon. Cloudy, with a high near 81. Chance of precipitation is 60%.
Tuesday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 64.
Wednesday
A 30 percent chance of showers. Mostly sunny, with a high near 81.
Wednesday Night
A 20 percent chance of showers. Partly cloudy, with a low around 56.
Thursday
A 20 percent chance of showers. Mostly sunny, with a high near 73.
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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:
1:44 am CST Mar 6, 2026
Forecast Valid:
1am CST Mar 6, 2026-6pm CDT Mar 12, 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