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

68°F

20°C

Humidity 96%
Wind Speed E 3 mph
Barometer 30.12 in (1019.4 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 29 Oct 2:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Cloudy, with a low around 67. East southeast wind around 5 mph.

    Low: 67 °F

    Cloudy

  • Thursday

    Thursday: A chance of showers and thunderstorms. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 77. East wind around 5 mph. Chance of precipitation is 40%.

    High: 77 °F

    Chance
    Showers and
    Patchy Fog

  • Thursday Night

    Thursday Night: A 10 percent chance of showers before 7pm. Mostly cloudy, with a low around 63. East wind around 5 mph.

    Low: 63 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Friday

    Friday: Showers likely, mainly between 1pm and 4pm. Mostly cloudy, with a high near 75. East wind 5 to 10 mph. Chance of precipitation is 60%.

    High: 75 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, with a low around 64. East northeast wind around 5 mph.

    Low: 64 °F

    Chance
    Showers

  • Saturday

    Saturday: A 20 percent chance of showers. Mostly cloudy, with a high near 81. East northeast wind around 5 mph becoming calm.

    High: 81 °F

    Slight Chance
    Showers

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 65. Calm wind.

    Low: 65 °F

    Mostly Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 83. Calm wind becoming east southeast around 5 mph.

    High: 83 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 66. Calm wind becoming south around 5 mph.

    Low: 66 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Cloudy, with a low around 67. East southeast wind around 5 mph.
Thursday
A chance of showers and thunderstorms. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 77. East wind around 5 mph. Chance of precipitation is 40%.
Thursday Night
A 10 percent chance of showers before 7pm. Mostly cloudy, with a low around 63. East wind around 5 mph.
Friday
Showers likely, mainly between 1pm and 4pm. Mostly cloudy, with a high near 75. East wind 5 to 10 mph. Chance of precipitation is 60%.
Friday Night
A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, with a low around 64. East northeast wind around 5 mph.
Saturday
A 20 percent chance of showers. Mostly cloudy, with a high near 81. East northeast wind around 5 mph becoming calm.
Saturday Night
Mostly cloudy, with a low around 65. Calm wind.
Sunday
Mostly cloudy, with a high near 83. Calm wind becoming east southeast around 5 mph.
Sunday Night
Mostly cloudy, with a low around 66. Calm wind becoming south around 5 mph.
Monday
Partly sunny, with a high near 84.
Monday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Tuesday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 80.
Tuesday Night
A 20 percent chance of showers. Mostly clear, with a low around 55.
Wednesday
Sunny, with a high near 77.
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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:
2:46 am CDT Oct 29, 2026
Forecast Valid:
3am CDT Oct 29, 2026-6pm CST Nov 4, 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