Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

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

Mostly Cloudy

86°F

30°C

Humidity 72%
Wind Speed S 12 mph
Barometer 30.04 in (1016.4 mb)
Dewpoint 76°F (24°C)
Visibility 10.00 mi
Heat Index96°F (36°C)
Last update 31 Jul 9:56 am CDT
Detailed forecast for

Caldwell County

Today
Partly cloudy this morning, then clearing. Hot with highs around 100. South winds 5 to 10 mph. Highest heat index readings up to 106.
Tonight
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
Partly cloudy in the morning, then becoming mostly sunny. Hot with highs around 100. North winds around 5 mph.
Sunday Night
Mostly clear. 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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332 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