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

77°F

25°C

Humidity 60%
Wind Speed N 5 mph
Barometer 29.97 in (1014.1 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 8 Oct 8:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Mostly clear, with a low around 68. North northeast wind around 5 mph becoming calm.

    Low: 68 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 90. Northeast wind around 5 mph.

    High: 90 °F

    Sunny

  • Friday Night

    Friday Night: Clear, with a low around 66. East northeast wind around 5 mph becoming calm.

    Low: 66 °F

    Clear

  • Saturday

    Saturday: Sunny, with a high near 90. North northwest wind around 5 mph becoming calm.

    High: 90 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 67. Calm wind becoming south around 5 mph.

    Low: 67 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 91. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 91 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 71. South southeast wind 5 to 10 mph.

    Low: 71 °F

    Mostly Clear

  • Columbus Day

    Columbus Day: Mostly sunny, with a high near 92. Light southeast wind becoming south 5 to 10 mph in the morning.

    High: 92 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 74. South wind around 5 mph.

    Low: 74 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 68. North northeast wind around 5 mph becoming calm.
Friday
Sunny, with a high near 90. Northeast wind around 5 mph.
Friday Night
Clear, with a low around 66. East northeast wind around 5 mph becoming calm.
Saturday
Sunny, with a high near 90. North northwest wind around 5 mph becoming calm.
Saturday Night
Clear, with a low around 67. Calm wind becoming south around 5 mph.
Sunday
Sunny, with a high near 91. South wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday Night
Mostly clear, with a low around 71. South southeast wind 5 to 10 mph.
Columbus Day
Mostly sunny, with a high near 92. Light southeast wind becoming south 5 to 10 mph in the morning.
Monday Night
Partly cloudy, with a low around 74. South wind around 5 mph.
Tuesday
A 20 percent chance of showers. Partly sunny, with a high near 93.
Tuesday Night
Partly cloudy, with a low around 75.
Wednesday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 93.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 75.
Thursday
A 30 percent chance of showers. Mostly sunny, with a high near 91.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
6:42 pm CDT Oct 8, 2026
Forecast Valid:
9pm CDT Oct 8, 2026-6pm CDT Oct 15, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation