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

64°F

18°C

Humidity 96%
Wind Speed SE 8 mph
Barometer 30.09 in (1018.5 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 22 Apr 12:56 am CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Overnight

    Overnight: A 30 percent chance of showers. Patchy fog. Otherwise, cloudy, with a low around 63. East southeast wind around 5 mph.

    Low: 63 °F

    Chance
    Showers and
    Patchy Fog

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 1pm. Areas of fog before 11am. Otherwise, mostly cloudy, with a high near 81. South wind 5 to 10 mph. Chance of precipitation is 40%.

    High: 81 °F

    Chance
    Showers and
    Areas Fog
    then Chance
    T-storms

  • Wednesday Night

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

    Low: 66 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 83. South wind 5 to 15 mph, with gusts as high as 20 mph.

    High: 83 °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 85. South wind 5 to 10 mph.

    High: 85 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 69. South wind 5 to 10 mph.

    Low: 69 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 89. South southeast wind 5 to 10 mph.

    High: 89 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 70. South southeast wind around 5 mph.

    Low: 70 °F

    Mostly Cloudy

Detailed Forecast

Overnight
A 30 percent chance of showers. Patchy fog. Otherwise, cloudy, with a low around 63. East southeast wind around 5 mph.
Wednesday
A chance of showers, with thunderstorms also possible after 1pm. Areas of fog before 11am. Otherwise, mostly cloudy, with a high near 81. South wind 5 to 10 mph. Chance of precipitation is 40%.
Wednesday Night
Mostly cloudy, with a low around 66. South wind 5 to 10 mph.
Thursday
Mostly cloudy, with a high near 83. 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 85. South wind 5 to 10 mph.
Friday Night
Mostly cloudy, with a low around 69. South wind 5 to 10 mph.
Saturday
Partly sunny, with a high near 89. South southeast wind 5 to 10 mph.
Saturday Night
Mostly cloudy, with a low around 70. South southeast wind around 5 mph.
Sunday
Mostly cloudy, with a high near 90.
Sunday Night
Mostly cloudy, with a low around 71.
Monday
Partly sunny, with a high near 92.
Monday Night
Partly cloudy, with a low around 68.
Tuesday
Partly sunny, with a high near 92.
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 am CDT Apr 22, 2026
Forecast Valid:
1am CDT Apr 22, 2026-6pm CDT Apr 28, 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