Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89° N Lon: 97.86° W Elev: 597 ft.

Mostly Cloudy

78°F

26°C

Humidity 90%
Wind Speed S 6 mph
Barometer 30.00 in (1014.8 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 31 Jul 1:56 am CDT
Detailed forecast for

Caldwell County

Rest Of Tonight
Partly cloudy. Near steady temperature in the upper 70s. South winds 5 to 10 mph.
Friday
Partly cloudy in the morning, then clearing. Hot with highs around 100. South winds 5 to 10 mph. Highest heat index readings up to 106.
Friday Night
Mostly clear. Lows in the mid 70s. South winds 5 to 10 mph.
Saturday
Mostly sunny. A slight chance of showers and thunderstorms in the afternoon. Highs in the upper 90s. Southwest winds around 5 mph. Highest heat index readings up to 107.
Saturday Night
Mostly cloudy with a chance of showers with a slight chance of thunderstorms in the evening, then partly cloudy after midnight. Lows in the upper 70s. West winds around 5 mph. Chance of rain 30 percent. Highest heat index readings up to 105 early in the evening.
Sunday And Sunday Night
Mostly clear. Hot. Highs around 100. Lows in the upper 70s.
Monday And Monday Night
Clear, hot. Highs around 100. Lows in the upper 70s. Highest heat index readings up to 105.
Tuesday And Tuesday Night
Mostly clear. Hot. Highs around 100. Lows in the upper 70s. Highest heat index readings up to 105.
Wednesday
Partly cloudy in the morning, then clearing. Highs in the upper 90s. Highest heat index readings up to 105.
Wednesday Night
Mostly clear. Lows in the upper 70s.
Thursday
Partly cloudy in the morning, then clearing. Highs in the upper 90s. Highest heat index readings up to 105.



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132 AM CDT Fri Jul 31 2026
 
 

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database