National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

81°F

27°C

Humidity 72%
Wind Speed E 6 mph
Barometer 29.88 in (1010.9 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index85°F (29°C)
Last update 6 Sep 8:56 pm CDT
Extended Forecast for

3 Miles NNW San Marcos Municipal Airport TX

  • Tonight

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

    Low: 75 °F

    Mostly Clear

  • Labor Day

    Labor Day: Mostly sunny, with a high near 98. Heat index values as high as 104. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 98 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 76. East southeast wind around 5 mph becoming south southwest after midnight.

    Low: 76 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny and hot, with a high near 99. Heat index values as high as 107. Calm wind becoming south southeast around 5 mph in the afternoon.

    High: 99 °F

    Hot

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 75. Southeast wind 5 to 10 mph.

    Low: 75 °F

    Mostly Clear

  • Wednesday

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

    High: 99 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 75. South wind around 5 mph.

    Low: 75 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 99. South southwest wind around 5 mph.

    High: 99 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 75. Southeast wind around 5 mph.

    Low: 75 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly clear, with a low around 75. East southeast wind around 5 mph becoming calm in the evening.
Labor Day
Mostly sunny, with a high near 98. Heat index values as high as 104. Calm wind becoming southeast around 5 mph in the afternoon.
Monday Night
Mostly clear, with a low around 76. East southeast wind around 5 mph becoming south southwest after midnight.
Tuesday
Sunny and hot, with a high near 99. Heat index values as high as 107. Calm wind becoming south southeast around 5 mph in the afternoon.
Tuesday Night
Mostly clear, with a low around 75. Southeast wind 5 to 10 mph.
Wednesday
Sunny and hot, with a high near 99. Calm wind becoming south southeast around 5 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 75. South wind around 5 mph.
Thursday
Sunny and hot, with a high near 99. South southwest wind around 5 mph.
Thursday Night
Mostly clear, with a low around 75. Southeast wind around 5 mph.
Friday
Sunny and hot, with a high near 100.
Friday Night
Mostly clear, with a low around 75.
Saturday
Sunny and hot, with a high near 100.
Saturday Night
Mostly clear, with a low around 75.
Sunday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 98.
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles NNW San Marcos Municipal Airport TX
 29.95°N 97.89°W (Elev. 646 ft)
Last Update:
6:44 pm CDT Sep 6, 2026
Forecast Valid:
9pm CDT Sep 6, 2026-6pm CDT Sep 13, 2026
 
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Additional Resources

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