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

76°F

24°C

Humidity 77%
Wind Speed SE 17 mph
Barometer 29.95 in (1013.4 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 16 Apr 9:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Increasing clouds, with a low around 68. South wind around 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Increasing
    Clouds

  • Friday

    Friday: Cloudy through mid morning, then gradual clearing, with a high near 90. South wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 90 °F

    Gradual
    Clearing

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 66. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 66 °F

    Mostly Cloudy

  • Saturday

    Saturday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 77. South wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 60%.

    High: 77 °F

    Chance
    Showers then
    Showers
    Likely

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms between 1am and 4am, then a chance of showers after 4am. Cloudy, with a low around 53. North northeast wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.

    Low: 53 °F

    Showers
    Likely

  • Sunday

    Sunday: Partly sunny, with a high near 72. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 72 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 54. East northeast wind 5 to 10 mph becoming light in the evening.

    Low: 54 °F

    Mostly Cloudy

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 66. East northeast wind around 5 mph.

    High: 66 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 57. East wind around 5 mph.

    Low: 57 °F

    Chance
    Showers

Detailed Forecast

Tonight
Increasing clouds, with a low around 68. South wind around 10 mph, with gusts as high as 20 mph.
Friday
Cloudy through mid morning, then gradual clearing, with a high near 90. South wind 10 to 15 mph, with gusts as high as 30 mph.
Friday Night
Mostly cloudy, with a low around 66. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Saturday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 77. South wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 60%.
Saturday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms between 1am and 4am, then a chance of showers after 4am. Cloudy, with a low around 53. North northeast wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.
Sunday
Partly sunny, with a high near 72. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Mostly cloudy, with a low around 54. East northeast wind 5 to 10 mph becoming light in the evening.
Monday
A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 66. East northeast wind around 5 mph.
Monday Night
A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 57. East wind around 5 mph.
Tuesday
A 40 percent chance of showers and thunderstorms. Cloudy, with a high near 72.
Tuesday Night
Mostly cloudy, with a low around 63.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81.
Wednesday Night
Mostly cloudy, with a low around 65.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, 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 97.91°W (Elev. 597 ft)
Last Update:
6:44 pm CDT Apr 16, 2026
Forecast Valid:
10pm CDT Apr 16, 2026-6pm CDT Apr 23, 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