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.

Fair

75°F

24°C

Humidity 90%
Wind Speed Calm
Barometer 30.03 in (1015.9 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 26 Aug 6:56 am CDT
Extended Forecast for

Mountain City TX

Heat Advisory August 26, 07:41am until August 26, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 26, 07:41am until August 26, 07:00pm

    NOW until 7:00pm Wed

    Heat Advisory

  • Today

    High: 102 °F

    Hot

  • Tonight

    Tonight: Partly cloudy, with a low around 77. South southwest wind around 5 mph.

    Low: 77 °F

    Partly Cloudy

  • Thursday

    Thursday: A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 101. Heat index values as high as 107. West southwest wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 40%.

    High: 101 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 74. East southeast wind around 5 mph becoming calm. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    T-storms then
    Chance
    Showers

  • Friday

    Friday: A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Mostly sunny and hot, with a high near 99. West southwest wind around 5 mph becoming east in the afternoon. Chance of precipitation is 20%.

    High: 99 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Friday Night

    Friday Night: A slight chance of thunderstorms before 7pm. Mostly clear, with a low around 75. East southeast wind around 5 mph becoming calm after midnight. Chance of precipitation is 10%.

    Low: 75 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 98. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 98 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 75. South wind around 5 mph.

    Low: 75 °F

    Clear

Detailed Forecast

Today
Sunny and hot, with a high near 102. Heat index values as high as 105. Southwest wind around 5 mph.
Tonight
Partly cloudy, with a low around 77. South southwest wind around 5 mph.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 101. Heat index values as high as 107. West southwest wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 74. East southeast wind around 5 mph becoming calm. Chance of precipitation is 30%.
Friday
A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Mostly sunny and hot, with a high near 99. West southwest wind around 5 mph becoming east in the afternoon. Chance of precipitation is 20%.
Friday Night
A slight chance of thunderstorms before 7pm. Mostly clear, with a low around 75. East southeast wind around 5 mph becoming calm after midnight. Chance of precipitation is 10%.
Saturday
Sunny, with a high near 98. Calm wind becoming southeast around 5 mph in the afternoon.
Saturday Night
Clear, with a low around 75. South wind around 5 mph.
Sunday
Sunny, with a high near 98. South southeast wind around 5 mph.
Sunday Night
Clear, with a low around 74.
Monday
Mostly sunny, with a high near 98.
Monday Night
Mostly clear, with a low around 74.
Tuesday
Mostly sunny, with a high near 98.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mountain City TX
 30.04°N 97.89°W (Elev. 837 ft)
Last Update:
6:42 am CDT Aug 26, 2026
Forecast Valid:
7am CDT Aug 26, 2026-6pm CDT Sep 1, 2026
 
Forecast Discussion
 
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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