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.

Fog/Mist

61°F

16°C

Humidity 97%
Wind Speed E 12 mph
Barometer 30.19 in (1021.9 mb)
Dewpoint 60°F (16°C)
Visibility 1.00 mi
Last update 21 Apr 12:56 pm CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • This Afternoon

    This Afternoon: Showers likely and possibly a thunderstorm. Cloudy, with a high near 69. East wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 69 °F

    Showers
    Likely

  • Tonight

    Tonight: A 30 percent chance of showers and thunderstorms, mainly before 10pm. Cloudy, with a low around 63. East wind 5 to 10 mph.

    Low: 63 °F

    Chance
    T-storms

  • Wednesday

    Wednesday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 80. South southeast wind 5 to 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Slight Chance
    T-storms then
    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 5 to 15 mph, with gusts as high as 20 mph.

    High: 84 °F

    Mostly Cloudy

  • Thursday Night

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

    Low: 68 °F

    Mostly Cloudy

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 86. South wind 5 to 10 mph.

    High: 86 °F

    Cloudy then
    Slight Chance
    T-storms

  • Friday Night

    Friday Night: Partly cloudy, with a low around 68. South wind around 5 mph.

    Low: 68 °F

    Partly Cloudy

  • Saturday

    Saturday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 87. South wind 5 to 10 mph.

    High: 87 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

Detailed Forecast

This Afternoon
Showers likely and possibly a thunderstorm. Cloudy, with a high near 69. East wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tonight
A 30 percent chance of showers and thunderstorms, mainly before 10pm. Cloudy, with a low around 63. East wind 5 to 10 mph.
Wednesday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 80. South southeast wind 5 to 10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
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 5 to 15 mph, with gusts as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 86. South wind 5 to 10 mph.
Friday Night
Partly cloudy, with a low around 68. South wind around 5 mph.
Saturday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 87. South wind 5 to 10 mph.
Saturday Night
Mostly cloudy, with a low around 69.
Sunday
Mostly cloudy, with a high near 89.
Sunday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70.
Monday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 91.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos Municipal Airport TX
 29.88°N 97.86°W (Elev. 600 ft)
Last Update:
12:44 pm CDT Apr 21, 2026
Forecast Valid:
1pm CDT Apr 21, 2026-6pm CDT Apr 27, 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