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

39°F

4°C

Humidity 86%
Wind Speed Calm
Barometer 30.46 in (1031.3 mb)
Dewpoint 35°F (2°C)
Visibility 10.00 mi
Last update 5 Feb 3:56 am CST
Extended Forecast for

San Marcos TX

  • Today

    Today: Sunny, with a high near 70. West northwest wind around 5 mph.

    High: 70 °F

    Sunny

  • Tonight

    Tonight: Clear, with a low around 45. West wind around 5 mph.

    Low: 45 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 80. West wind around 5 mph becoming east northeast in the afternoon.

    High: 80 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 47. Calm wind.

    Low: 47 °F

    Clear

  • Saturday

    Saturday: Sunny, with a high near 80. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 80 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 49. South southeast wind around 5 mph becoming calm in the evening.

    Low: 49 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 78. Calm wind becoming south around 5 mph in the morning.

    High: 78 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 52. South southeast wind around 5 mph becoming calm after midnight.

    Low: 52 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 77. Light south southwest wind becoming south 5 to 10 mph in the morning.

    High: 77 °F

    Mostly Cloudy

Detailed Forecast

Today
Sunny, with a high near 70. West northwest wind around 5 mph.
Tonight
Clear, with a low around 45. West wind around 5 mph.
Friday
Sunny, with a high near 80. West wind around 5 mph becoming east northeast in the afternoon.
Friday Night
Clear, with a low around 47. Calm wind.
Saturday
Sunny, with a high near 80. Calm wind becoming southeast around 5 mph in the afternoon.
Saturday Night
Partly cloudy, with a low around 49. South southeast wind around 5 mph becoming calm in the evening.
Sunday
Partly sunny, with a high near 78. Calm wind becoming south around 5 mph in the morning.
Sunday Night
Mostly cloudy, with a low around 52. South southeast wind around 5 mph becoming calm after midnight.
Monday
Mostly cloudy, with a high near 77. Light south southwest wind becoming south 5 to 10 mph in the morning.
Monday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 56.
Tuesday
A 30 percent chance of showers. Mostly cloudy, with a high near 77.
Tuesday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 54.
Wednesday
Mostly sunny, with a high near 82.
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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:
4:33 am CST Feb 5, 2026
Forecast Valid:
4am CST Feb 5, 2026-6pm CST Feb 11, 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