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

67°F

19°C

Humidity 47%
Wind Speed E 8 mph
Barometer 30.25 in (1023.8 mb)
Dewpoint 46°F (8°C)
Visibility 10.00 mi
Last update 19 Apr 4:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 20 percent chance of showers. Mostly cloudy, with a high near 70. East wind around 10 mph.

    High: 70 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: A slight chance of showers before 10pm, then a chance of showers after 1am. Cloudy, with a low around 54. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.

    Low: 54 °F

    Chance
    Showers

  • Monday

    Monday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 7am. Mostly cloudy, with a high near 64. East wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    High: 64 °F

    Showers
    Likely

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm. Cloudy, with a low around 57. East northeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 70%.

    Low: 57 °F

    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm. Cloudy, with a high near 69. East wind 5 to 10 mph. Chance of precipitation is 70%.

    High: 69 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 63. East southeast wind 5 to 10 mph.

    Low: 63 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. South southeast wind 5 to 10 mph.

    High: 80 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 66. South southeast wind 5 to 10 mph.

    Low: 66 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 84 °F

    Mostly Cloudy

Detailed Forecast

This Afternoon
A 20 percent chance of showers. Mostly cloudy, with a high near 70. East wind around 10 mph.
Tonight
A slight chance of showers before 10pm, then a chance of showers after 1am. Cloudy, with a low around 54. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.
Monday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 7am. Mostly cloudy, with a high near 64. East wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Monday Night
Showers likely and possibly a thunderstorm. Cloudy, with a low around 57. East northeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 70%.
Tuesday
Showers likely and possibly a thunderstorm. Cloudy, with a high near 69. East wind 5 to 10 mph. Chance of precipitation is 70%.
Tuesday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 63. East southeast wind 5 to 10 mph.
Wednesday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80. South southeast wind 5 to 10 mph.
Wednesday Night
Mostly cloudy, with a low around 66. South southeast wind 5 to 10 mph.
Thursday
Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 68.
Friday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 88.
Friday Night
Mostly cloudy, with a low around 68.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86.
Saturday Night
Mostly cloudy, with a low around 67.
Sunday
A slight chance of showers and thunderstorms. Mostly cloudy, with a high near 84.
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:
2:46 pm CDT Apr 19, 2026
Forecast Valid:
5pm CDT Apr 19, 2026-6pm CDT Apr 26, 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