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.

Fair

82°F

28°C

Humidity 72%
Wind Speed S 13 mph
Barometer 29.95 in (1013.2 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index87°F (31°C)
Last update 13 Aug 12:56 am CDT
Extended Forecast for

Mountain City TX

  • Overnight

    Overnight: Partly cloudy, with a low around 75. South wind around 10 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Partly Cloudy

  • Thursday

    Thursday: Partly sunny, then gradually becoming sunny and hot, with a high near 100. Heat index values as high as 107. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 100 °F

    Hot

  • Thursday Night

    Thursday Night: Increasing clouds, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 75 °F

    Increasing
    Clouds

  • Friday

    Friday: Mostly sunny, with a high near 97. Heat index values as high as 107. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 97 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 76. South wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 76 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 98. South wind 5 to 10 mph.

    High: 98 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 73. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 73 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 98. South southeast wind around 5 mph.

    High: 98 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 74. South southeast wind 5 to 10 mph.

    Low: 74 °F

    Mostly Clear

Detailed Forecast

Overnight
Partly cloudy, with a low around 75. South wind around 10 mph, with gusts as high as 20 mph.
Thursday
Partly sunny, then gradually becoming sunny and hot, with a high near 100. Heat index values as high as 107. South wind 10 to 15 mph, with gusts as high as 25 mph.
Thursday Night
Increasing clouds, with a low around 75. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday
Mostly sunny, with a high near 97. Heat index values as high as 107. South wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
Partly cloudy, with a low around 76. South wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday
Sunny, with a high near 98. South wind 5 to 10 mph.
Saturday Night
Mostly clear, with a low around 73. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday
Sunny, with a high near 98. South southeast wind around 5 mph.
Sunday Night
Mostly clear, with a low around 74. South southeast wind 5 to 10 mph.
Monday
Sunny and hot, with a high near 99.
Monday Night
Mostly clear, with a low around 75.
Tuesday
Sunny and hot, with a high near 99.
Tuesday Night
Mostly clear, with a low around 76.
Wednesday
Sunny and hot, with a high near 99.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mountain City TX
 30.04°N 97.89°W (Elev. 837 ft)
Last Update:
12:42 am CDT Aug 13, 2026
Forecast Valid:
1am CDT Aug 13, 2026-6pm CDT Aug 19, 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