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

78°F

26°C

Humidity 26%
Wind Speed S 14 G 23 mph
Barometer 29.99 in (1015.2 mb)
Dewpoint 40°F (4°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 13 Mar 2:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Sunny, with a high near 79. South wind around 10 mph, with gusts as high as 20 mph.

    High: 79 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 52. South wind around 5 mph.

    Low: 52 °F

    Mostly Clear

  • Saturday

    Saturday: Partly sunny, then gradually becoming sunny, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 84 °F

    Becoming
    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 63. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 63 °F

    Increasing
    Clouds

  • Sunday

    Sunday: Partly sunny, with a high near 91. South wind 10 to 15 mph becoming west in the afternoon. Winds could gust as high as 25 mph.

    High: 91 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 40. Breezy, with a north wind 15 to 25 mph, with gusts as high as 35 mph.

    Low: 40 °F

    Mostly Clear
    and Breezy

  • Monday

    Monday: Mostly sunny, with a high near 57. North wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 57 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 37. North northeast wind around 5 mph becoming calm in the evening.

    Low: 37 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 67. Light south southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph.

    High: 67 °F

    Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 79. South wind around 10 mph, with gusts as high as 20 mph.
Tonight
Mostly clear, with a low around 52. South wind around 5 mph.
Saturday
Partly sunny, then gradually becoming sunny, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday Night
Increasing clouds, with a low around 63. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Sunday
Partly sunny, with a high near 91. South wind 10 to 15 mph becoming west in the afternoon. Winds could gust as high as 25 mph.
Sunday Night
Mostly clear, with a low around 40. Breezy, with a north wind 15 to 25 mph, with gusts as high as 35 mph.
Monday
Mostly sunny, with a high near 57. North wind 10 to 15 mph, with gusts as high as 30 mph.
Monday Night
Mostly cloudy, with a low around 37. North northeast wind around 5 mph becoming calm in the evening.
Tuesday
Sunny, with a high near 67. Light south southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph.
Tuesday Night
Mostly clear, with a low around 46.
Wednesday
Sunny, with a high near 77.
Wednesday Night
Mostly clear, with a low around 53.
Thursday
Sunny, with a high near 83.
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 97.94°W (Elev. 577 ft)
Last Update:
2:46 pm CDT Mar 13, 2026
Forecast Valid:
3pm CDT Mar 13, 2026-6pm CDT Mar 19, 2026
 
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