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

89°F

32°C

Humidity 52%
Wind Speed S 10 mph
Barometer 29.96 in (1013.7 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index94°F (34°C)
Last update 26 Aug 10:56 pm CDT
Extended Forecast for

Martindale TX

Heat Advisory August 26, 11:42pm until August 27, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 26, 11:42pm until August 27, 07:00pm

    NOW until 7:00pm Thu

    Heat Advisory

  • Tonight

    Low: 79 °F

    Partly Cloudy

  • Thursday

    Thursday: A slight chance of showers before 10am, then a chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 102. Heat index values as high as 108. Southwest wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 40%.

    High: 102 °F

    Slight Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 30 percent chance of showers and thunderstorms before 10pm. Partly cloudy, with a low around 77. South southwest wind around 5 mph becoming calm in the evening.

    Low: 77 °F

    Chance
    T-storms then
    Partly Cloudy

  • Friday

    Friday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 99. Heat index values as high as 107. Calm wind becoming east southeast around 5 mph in the afternoon.

    High: 99 °F

    Sunny then
    Slight Chance
    T-storms

  • Friday Night

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

    Low: 76 °F

    Partly Cloudy

  • 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 5 to 10 mph becoming south after midnight.

    Low: 74 °F

    Mostly Clear

  • Sunday

    Sunday: A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 98. Calm wind becoming south southeast around 5 mph in the morning.

    High: 98 °F

    Sunny then
    Slight Chance
    T-storms

Detailed Forecast

Tonight
Partly cloudy, with a low around 79. South southwest wind around 5 mph.
Thursday
A slight chance of showers before 10am, then a chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 102. Heat index values as high as 108. Southwest wind around 5 mph becoming calm in the afternoon. Chance of precipitation is 40%.
Thursday Night
A 30 percent chance of showers and thunderstorms before 10pm. Partly cloudy, with a low around 77. South southwest wind around 5 mph becoming calm in the evening.
Friday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 99. Heat index values as high as 107. Calm wind becoming east southeast around 5 mph in the afternoon.
Friday Night
Partly cloudy, with a low around 76. East southeast wind around 5 mph becoming calm after midnight.
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 5 to 10 mph becoming south after midnight.
Sunday
A 20 percent chance of showers and thunderstorms after 1pm. Sunny, with a high near 98. Calm wind becoming south southeast around 5 mph in the morning.
Sunday Night
Mostly clear, with a low around 74. Southeast wind 5 to 10 mph.
Monday
Mostly sunny, with a high near 98.
Monday Night
Mostly clear, with a low around 75.
Tuesday
Mostly sunny, with a high near 98.
Tuesday Night
Mostly clear, with a low around 74.
Wednesday
Mostly sunny and hot, with a high near 99.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Martindale TX
 29.84°N 97.83°W (Elev. 502 ft)
Last Update:
11:32 pm CDT Aug 26, 2026
Forecast Valid:
11pm CDT Aug 26, 2026-6pm CDT Sep 2, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation