National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

74°F

23°C

Humidity 88%
Wind Speed S 14 mph
Barometer 30.10 in (1018.5 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 12 Apr 10:56 am CDT
Extended Forecast for

San Marcos TX

Flood Watch until April 13, 07:00am
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch until April 13, 07:00am

    NOW until 7:00am Mon

    Flood Watch

  • Today

    High: 79 °F

    T-storms
    Likely

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly before 1am. Cloudy, with a low around 69. South wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 69 °F

    Showers
    Likely then
    Chance
    T-storms

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 84 °F

    Cloudy then
    Slight Chance
    T-storms

  • Monday Night

    Monday Night: Increasing clouds, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 84 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 68 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms after 1pm. 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
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Slight Chance
    T-storms

Detailed Forecast

Today
Showers likely and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. Mostly cloudy, with a high near 79. South wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.
Tonight
Showers and thunderstorms likely, mainly before 1am. Cloudy, with a low around 69. South wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 84. South wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
Increasing clouds, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.
Tuesday
Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 68. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday
Partly sunny, with a high near 88. South wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Partly cloudy, with a low around 68.
Friday
Mostly cloudy, with a high near 89.
Friday Night
Mostly cloudy, with a low around 69.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86.
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:
10:50 am CDT Apr 12, 2026
Forecast Valid:
11am CDT Apr 12, 2026-6pm CDT Apr 18, 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