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.

Overcast

71°F

22°C

Humidity 87%
Wind Speed S 9 mph
Barometer 29.97 in (1014.2 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 16 Apr 2:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Cloudy, with a low around 69. South wind around 5 mph.

    Low: 69 °F

    Cloudy

  • Thursday

    Thursday: Cloudy, then gradually becoming mostly sunny, with a high near 88. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 88 °F

    Decreasing
    Clouds

  • Thursday Night

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

    Low: 68 °F

    Increasing
    Clouds

  • Friday

    Friday: 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

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 67. South southeast wind 5 to 15 mph, with gusts as high as 30 mph.

    Low: 67 °F

    Mostly Cloudy

  • Saturday

    Saturday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. Cloudy, with a high near 77. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph.

    High: 77 °F

    Slight Chance
    T-storms then
    Chance
    T-storms

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers. Cloudy, with a low around 54. North northeast wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.

    Low: 54 °F

    Showers
    Likely

  • Sunday

    Sunday: A 20 percent chance of showers. Mostly cloudy, with a high near 69. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 69 °F

    Slight Chance
    Showers

  • Sunday Night

    Sunday Night: A 30 percent chance of showers, mainly after 1am. Cloudy, with a low around 54. East northeast wind 5 to 10 mph.

    Low: 54 °F

    Chance
    Showers

Detailed Forecast

Overnight
Cloudy, with a low around 69. South wind around 5 mph.
Thursday
Cloudy, then gradually becoming mostly sunny, with a high near 88. South wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Increasing clouds, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Friday
Cloudy, then gradually becoming mostly sunny, with a high near 89. South wind 10 to 15 mph, with gusts as high as 30 mph.
Friday Night
Mostly cloudy, with a low around 67. South southeast wind 5 to 15 mph, with gusts as high as 30 mph.
Saturday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Cloudy, with a high near 77. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph.
Saturday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers. Cloudy, with a low around 54. North northeast wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.
Sunday
A 20 percent chance of showers. Mostly cloudy, with a high near 69. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
A 30 percent chance of showers, mainly after 1am. Cloudy, with a low around 54. East northeast wind 5 to 10 mph.
Monday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Cloudy, with a high near 65. Chance of precipitation is 60%.
Monday Night
A 30 percent chance of showers and thunderstorms. Cloudy, with a low around 58.
Tuesday
A 30 percent chance of showers and thunderstorms. Cloudy, with a high near 75.
Tuesday Night
Mostly cloudy, with a low around 64.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82.
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:
2:42 am CDT Apr 16, 2026
Forecast Valid:
3am CDT Apr 16, 2026-6pm CDT Apr 22, 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