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

100°F

38°C

Humidity 41%
Wind Speed S 9 mph
Barometer 29.96 in (1013.5 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index110°F (43°C)
Last update 27 Aug 1:56 pm CDT
Extended Forecast for

Lockhart TX

Heat Advisory August 27, 02:26pm until August 27, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 27, 02:26pm until August 27, 07:00pm

    NOW until 7:00pm Thu

    Heat Advisory

  • This Afternoon

    High: 102 °F

    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 76. South southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.

    Low: 76 °F

    Chance
    T-storms then
    Slight Chance
    Showers

  • Friday

    Friday: Sunny and hot, with a high near 102. Heat index values as high as 107. Calm wind becoming east around 5 mph in the afternoon.

    High: 102 °F

    Hot

  • Friday Night

    Friday Night: Mostly clear, with a low around 76. East southeast wind around 5 mph becoming calm after midnight.

    Low: 76 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny and hot, with a high near 100. Calm wind becoming east southeast around 5 mph in the afternoon.

    High: 100 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 75. East southeast wind 5 to 10 mph becoming south after midnight.

    Low: 75 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 100. Calm wind becoming south southeast around 5 mph in the morning.

    High: 100 °F

    Hot

  • Sunday Night

    Sunday Night: Clear, with a low around 74. Southeast wind 5 to 10 mph.

    Low: 74 °F

    Clear

Detailed Forecast

This Afternoon
A 40 percent chance of showers and thunderstorms. Mostly sunny and hot, with a high near 102. Heat index values as high as 108. Calm wind becoming west southwest around 5 mph.
Tonight
A chance of showers and thunderstorms before 10pm, then a slight chance of showers between 10pm and 1am. Partly cloudy, with a low around 76. South southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.
Friday
Sunny and hot, with a high near 102. Heat index values as high as 107. Calm wind becoming east around 5 mph in the afternoon.
Friday Night
Mostly clear, with a low around 76. East southeast wind around 5 mph becoming calm after midnight.
Saturday
Sunny and hot, with a high near 100. Calm wind becoming east southeast around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 75. East southeast wind 5 to 10 mph becoming south after midnight.
Sunday
Sunny and hot, with a high near 100. Calm wind becoming south southeast around 5 mph in the morning.
Sunday Night
Clear, with a low around 74. Southeast wind 5 to 10 mph.
Monday
Mostly sunny and hot, with a high near 99. South wind 5 to 10 mph.
Monday Night
Mostly clear, with a low around 75.
Tuesday
Mostly sunny and hot, with a high near 100.
Tuesday Night
Mostly clear, with a low around 75.
Wednesday
Mostly sunny and hot, with a high near 99.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lockhart TX
 29.88°N 97.68°W (Elev. 525 ft)
Last Update:
1:24 pm CDT Aug 27, 2026
Forecast Valid:
2pm CDT Aug 27, 2026-6pm CDT Sep 2, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation