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.

Mostly Cloudy

73°F

23°C

Humidity 94%
Wind Speed S 8 mph
Barometer 29.74 in (1006.3 mb)
Dewpoint 71°F (22°C)
Visibility 4.00 mi
Last update 26 Apr 2:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Mostly cloudy, with a low around 71. South wind around 5 mph.

    Low: 71 °F

    Mostly Cloudy

  • Sunday

    Sunday: Cloudy, then gradually becoming mostly sunny, with a high near 91. South southeast wind 5 to 10 mph.

    High: 91 °F

    Decreasing
    Clouds

  • Sunday Night

    Sunday Night: Increasing clouds, with a low around 72. South southeast wind around 10 mph.

    Low: 72 °F

    Increasing
    Clouds

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 92. South wind around 5 mph.

    High: 92 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 72. South southeast wind around 5 mph.

    Low: 72 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 94 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 71. South wind 5 to 10 mph.

    Low: 71 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 92. South wind around 5 mph becoming east in the afternoon.

    High: 92 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. Northeast wind 5 to 10 mph.

    Low: 69 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
Mostly cloudy, with a low around 71. South wind around 5 mph.
Sunday
Cloudy, then gradually becoming mostly sunny, with a high near 91. South southeast wind 5 to 10 mph.
Sunday Night
Increasing clouds, with a low around 72. South southeast wind around 10 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 92. South wind around 5 mph.
Monday Night
Mostly cloudy, with a low around 72. South southeast wind around 5 mph.
Tuesday
Partly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday Night
Mostly cloudy, with a low around 71. South wind 5 to 10 mph.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 92. South wind around 5 mph becoming east in the afternoon.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. Northeast wind 5 to 10 mph.
Thursday
A 30 percent chance of showers and thunderstorms, mainly after 1pm. Cloudy, with a high near 84.
Thursday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 67.
Friday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57.
Saturday
A 20 percent chance of showers. Partly sunny, with a high near 71.
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 am CDT Apr 26, 2026
Forecast Valid:
3am CDT Apr 26, 2026-6pm CDT May 2, 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