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 32%
Wind Speed SE 3 mph
Barometer 29.92 in (1012.3 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Heat Index104°F (40°C)
Last update 26 Aug 6:56 pm CDT
Extended Forecast for

Lockhart TX

Heat Advisory August 26, 07:46pm until August 27, 07:00pm
Click here for hazard details and duration
Heat Advisory
  •  
    Heat Advisory August 26, 07:46pm until August 27, 07:00pm

    NOW until 7:00pm Thu

    Heat Advisory

  • Tonight

    Low: 78 °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 107. 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, mainly before 10pm. Mostly clear, with a low around 76. South southeast wind around 5 mph becoming calm in the evening.

    Low: 76 °F

    Chance
    T-storms

  • 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 105. 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 75. East southeast wind around 5 mph becoming calm after midnight.

    Low: 75 °F

    Partly Cloudy

  • Saturday

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

    High: 99 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 73. East southeast wind 5 to 10 mph becoming south after midnight.

    Low: 73 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 99. Light south wind becoming southeast 5 to 10 mph in the morning.

    High: 99 °F

    Hot

Detailed Forecast

Tonight
Partly cloudy, with a low around 78. South 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 107. 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, mainly before 10pm. Mostly clear, with a low around 76. South southeast 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 105. Calm wind becoming east southeast around 5 mph in the afternoon.
Friday Night
Partly cloudy, with a low around 75. East southeast wind around 5 mph becoming calm after midnight.
Saturday
Sunny and hot, with a high near 99. Calm wind becoming east southeast around 5 mph in the afternoon.
Saturday Night
Mostly clear, with a low around 73. East southeast wind 5 to 10 mph becoming south after midnight.
Sunday
Sunny and hot, with a high near 99. Light south wind becoming southeast 5 to 10 mph in the morning.
Sunday Night
Mostly clear, with a low around 73. Southeast wind 5 to 10 mph.
Monday
Mostly sunny, with a high near 98.
Monday Night
Mostly clear, with a low around 74.
Tuesday
Mostly sunny and hot, with a high near 99.
Tuesday Night
Mostly clear, with a low around 74.
Wednesday
Mostly sunny and hot, with a high near 100.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lockhart TX
 29.88°N 97.68°W (Elev. 525 ft)
Last Update:
7:28 pm CDT Aug 26, 2026
Forecast Valid:
7pm CDT Aug 26, 2026-6pm CDT Sep 2, 2026
 
Forecast Discussion
 
Get as KML Get as XML

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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