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

99°F

37°C

Humidity 41%
Wind Speed W 6 mph
Barometer 29.89 in (1011.2 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index108°F (42°C)
Last update 27 Aug 3:56 pm CDT
Extended Forecast for

4 Miles SE Wimberley TX

Heat Advisory August 27, 04:45pm until August 27, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 27, 04:45pm until August 27, 07:00pm

    NOW until 7:00pm Thu

    Heat Advisory

  • This Afternoon

    High: 100 °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 75. West southwest wind around 5 mph becoming calm. Chance of precipitation is 30%.

    Low: 75 °F

    Chance
    T-storms then
    Slight Chance
    Showers

  • Friday

    Friday: Sunny and hot, with a high near 100. Heat index values as high as 109. Calm wind becoming east around 5 mph in the afternoon.

    High: 100 °F

    Hot

  • Friday Night

    Friday Night: Mostly clear, with a low around 75. East wind around 5 mph becoming calm in the evening.

    Low: 75 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny and hot, with a high near 99. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 99 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 74. East southeast wind around 5 mph becoming south after midnight.

    Low: 74 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 98. Calm wind becoming south around 5 mph in the morning.

    High: 98 °F

    Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 73. Southeast wind 5 to 10 mph.

    Low: 73 °F

    Clear

Detailed Forecast

This Afternoon
A 50 percent chance of showers and thunderstorms. Partly sunny and hot, with a high near 100. Heat index values as high as 107. East wind 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 75. West southwest wind around 5 mph becoming calm. Chance of precipitation is 30%.
Friday
Sunny and hot, with a high near 100. Heat index values as high as 109. Calm wind becoming east around 5 mph in the afternoon.
Friday Night
Mostly clear, with a low around 75. East wind around 5 mph becoming calm in the evening.
Saturday
Sunny and hot, with a high near 99. Calm wind becoming southeast around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 74. East southeast wind around 5 mph becoming south after midnight.
Sunday
Sunny, with a high near 98. Calm wind becoming south around 5 mph in the morning.
Sunday Night
Clear, with a low around 73. Southeast wind 5 to 10 mph.
Monday
Sunny, with a high near 97. South wind around 5 mph.
Monday Night
Mostly clear, with a low around 74.
Tuesday
Mostly sunny, with a high near 98.
Tuesday Night
Mostly clear, with a low around 74.
Wednesday
Mostly sunny, with a high near 97.
Wednesday Night
Mostly clear, with a low around 74.
Thursday
Sunny, with a high near 98.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SE Wimberley TX
 29.97°N 98.05°W (Elev. 1050 ft)
Last Update:
2:46 pm CDT Aug 27, 2026
Forecast Valid:
4pm CDT Aug 27, 2026-6pm CDT Sep 3, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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