Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

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

Fair

80°F

27°C

Humidity 79%
Wind Speed S 7 mph
Barometer 30.01 in (1015.4 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 31 Aug 12:56 am CDT
Detailed forecast for

Hays County

Tonight
Mostly clear this evening, then becoming partly cloudy. Lows in the mid 70s. South winds 5 to 10 mph.
Monday
Mostly sunny. Highs in the upper 90s. South winds 5 to 10 mph.
Monday Night
Mostly clear. Lows in the mid 70s. Southeast winds 5 to 10 mph, becoming south after midnight.
Tuesday
Mostly sunny. Highs in the upper 90s. Southwest winds around 5 mph, becoming southeast around 5 mph in the afternoon. Highest heat index readings up to 107.
Tuesday Night
Mostly clear in the evening, then becoming partly cloudy. Lows in the mid 70s. South winds around 5 mph.
Wednesday
Mostly sunny in the morning, then partly cloudy with a slight chance of showers and thunderstorms in the afternoon. Highs in the upper 90s. Highest heat index readings up to 110.
Wednesday Night
Partly cloudy. Lows in the mid 70s.
Thursday
Partly cloudy in the morning, then mostly sunny with a slight chance of showers and thunderstorms in the afternoon. Highs in the upper 90s. Highest heat index readings up to 105.
Thursday Night
Partly cloudy in the evening, then clearing. Lows in the mid 70s.
Friday
Partly cloudy in the morning, then clearing. Highs in the upper 90s. Highest heat index readings up to 105.
Friday Night
Mostly clear. Lows in the mid 70s.
Saturday
Partly cloudy. Highs in the upper 90s. Highest heat index readings up to 105.
Saturday Night And Sunday
Mostly clear. Lows in the mid 70s. Highs in the upper 90s. Highest heat index readings up to 110.



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412 PM CDT Sun Aug 30 2026
 
 

Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database