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 77%
Wind Speed SE 16 G 20 mph
Barometer 29.87 in (1010.8 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index88°F (31°C)
Last update 18 May 8:56 pm CDT
Extended Forecast for

Mountain City TX

  • Tonight

    Tonight: Increasing clouds, with a low around 77. South wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 77 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: A 30 percent chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 90. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 90 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 7pm, then showers likely and possibly a thunderstorm between 7pm and 1am, then a chance of showers and thunderstorms after 1am. Some of the storms could produce heavy rainfall. Increasing clouds, with a low around 71. Southeast wind 5 to 15 mph becoming east northeast after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between 1 and 2 inches possible.

    Low: 71 °F

    Heavy Rain

  • Wednesday

    Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. North northeast wind around 5 mph becoming southeast in the afternoon. Chance of precipitation is 60%.

    High: 84 °F

    Chance
    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 72. East southeast wind around 5 mph. Chance of precipitation is 70%.

    Low: 72 °F

    Showers
    Likely

  • Thursday

    Thursday: Showers and possibly a thunderstorm. High near 82. Southeast wind 5 to 10 mph. Chance of precipitation is 90%.

    High: 82 °F

    Showers then
    T-storms

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 70. South southeast wind around 5 mph. Chance of precipitation is 70%.

    Low: 70 °F

    Showers
    Likely

  • Friday

    Friday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. South wind 5 to 10 mph. Chance of precipitation is 60%.

    High: 84 °F

    Chance
    T-storms then
    Showers
    Likely

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70. South wind around 5 mph.

    Low: 70 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Increasing clouds, with a low around 77. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday
A 30 percent chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 90. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
A chance of showers and thunderstorms before 7pm, then showers likely and possibly a thunderstorm between 7pm and 1am, then a chance of showers and thunderstorms after 1am. Some of the storms could produce heavy rainfall. Increasing clouds, with a low around 71. Southeast wind 5 to 15 mph becoming east northeast after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between 1 and 2 inches possible.
Wednesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. North northeast wind around 5 mph becoming southeast in the afternoon. Chance of precipitation is 60%.
Wednesday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 72. East southeast wind around 5 mph. Chance of precipitation is 70%.
Thursday
Showers and possibly a thunderstorm. High near 82. Southeast wind 5 to 10 mph. Chance of precipitation is 90%.
Thursday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 70. South southeast wind around 5 mph. Chance of precipitation is 70%.
Friday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 84. South wind 5 to 10 mph. Chance of precipitation is 60%.
Friday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70. South wind around 5 mph.
Saturday
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1pm. High near 82. Chance of precipitation is 80%.
Saturday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.
Sunday
Showers and thunderstorms likely. Mostly cloudy, with a high near 82. Chance of precipitation is 70%.
Sunday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 70.
Memorial Day
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 84.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Mountain City TX
 30.04°N 97.89°W (Elev. 837 ft)
Last Update:
6:42 pm CDT May 18, 2026
Forecast Valid:
9pm CDT May 18, 2026-6pm CDT May 25, 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