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.

A Few Clouds

70°F

21°C

Humidity 82%
Wind Speed S 9 mph
Barometer 29.99 in (1014.9 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 31 Mar 11:56 pm CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Increasing clouds, with a low around 67. South wind 5 to 10 mph.

    Low: 67 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 89. South wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 89 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 68. South wind 10 to 20 mph, with gusts as high as 30 mph.

    Low: 68 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Thursday

    Thursday: A 50 percent chance of showers and thunderstorms, mainly between 7am and 1pm. Cloudy, with a high near 84. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 84 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 69 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 87 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 68. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.

    Low: 68 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: Showers and possibly a thunderstorm. High near 78. South wind 10 to 15 mph becoming north northwest in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    High: 78 °F

    Showers

  • Saturday Night

    Saturday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 53. North northeast wind around 15 mph, with gusts as high as 30 mph.

    Low: 53 °F

    Chance
    T-storms

Detailed Forecast

Overnight
Increasing clouds, with a low around 67. South wind 5 to 10 mph.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 89. South wind 10 to 15 mph, with gusts as high as 30 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms after 4am. Increasing clouds, with a low around 68. South wind 10 to 20 mph, with gusts as high as 30 mph.
Thursday
A 50 percent chance of showers and thunderstorms, mainly between 7am and 1pm. Cloudy, with a high near 84. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Thursday Night
Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Friday
Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 68. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.
Saturday
Showers and possibly a thunderstorm. High near 78. South wind 10 to 15 mph becoming north northwest in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Saturday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 53. North northeast wind around 15 mph, with gusts as high as 30 mph.
Sunday
A chance of showers and thunderstorms. Cloudy, with a high near 65. Chance of precipitation is 30%.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 51.
Monday
Mostly cloudy, with a high near 68.
Monday Night
Mostly cloudy, with a low around 50.
Tuesday
Mostly cloudy, with a high near 72.
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:
12:02 am CDT Apr 1, 2026
Forecast Valid:
12am CDT Apr 1, 2026-6pm CDT Apr 7, 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