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.

Partly Cloudy

34°C

94°F

Humidity 49%
Wind Speed SE 17 km/h
Barometer 1013.8 mb (29.96 in)
Dewpoint 22°C (72°F)
Visibility 16 km
Heat Index39°C (102°F)
Last update 15 Jul 4:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Increasing clouds, with a low around 24. South southeast wind 10 to 20 km/h, with gusts as high as 30 km/h.

    Low: 24 °C

    Increasing
    Clouds

  • Wednesday

    Wednesday: Mostly cloudy, then gradually becoming sunny, with a high near 36. Heat index values as high as 39. South wind 10 to 15 km/h, with gusts as high as 35 km/h.

    High: 36 °C

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 22. South southeast wind 10 to 20 km/h, with gusts as high as 35 km/h.

    Low: 22 °C

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 35. Heat index values as high as 38. South wind 5 to 10 km/h.

    High: 35 °C

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 22. South southeast wind 5 to 10 km/h.

    Low: 22 °C

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 33. South southeast wind 5 to 10 km/h.

    High: 33 °C

    Partly Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 23. East southeast wind around 10 km/h becoming south after midnight.

    Low: 23 °C

    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 36. South wind 10 to 15 km/h.

    High: 36 °C

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 24. South southeast wind 10 to 15 km/h.

    Low: 24 °C

    Partly Cloudy

Detailed Forecast

Tonight
Increasing clouds, with a low around 24. South southeast wind 10 to 20 km/h, with gusts as high as 30 km/h.
Wednesday
Mostly cloudy, then gradually becoming sunny, with a high near 36. Heat index values as high as 39. South wind 10 to 15 km/h, with gusts as high as 35 km/h.
Wednesday Night
Partly cloudy, with a low around 22. South southeast wind 10 to 20 km/h, with gusts as high as 35 km/h.
Thursday
Mostly sunny, with a high near 35. Heat index values as high as 38. South wind 5 to 10 km/h.
Thursday Night
Partly cloudy, with a low around 22. South southeast wind 5 to 10 km/h.
Friday
Partly sunny, with a high near 33. South southeast wind 5 to 10 km/h.
Friday Night
Mostly cloudy, with a low around 23. East southeast wind around 10 km/h becoming south after midnight.
Saturday
Mostly sunny, with a high near 36. South wind 10 to 15 km/h.
Saturday Night
Partly cloudy, with a low around 24. South southeast wind 10 to 15 km/h.
Sunday
Mostly sunny, with a high near 36.
Sunday Night
Partly cloudy, with a low around 24.
Monday
Mostly sunny, with a high near 36.
Monday Night
Partly cloudy, with a low around 24.
Tuesday
Mostly sunny, with a high near 36.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 m)
Last Update:
2:44 pm CDT Jul 15, 2025
Forecast Valid:
5pm CDT Jul 15, 2025-6pm CDT Jul 22, 2025
 
Forecast Discussion
 
Get as KML Get as XML

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