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

76°F

24°C

Humidity 60%
Wind Speed SE 8 mph
Barometer 30.01 in (1015.3 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 10 Oct 9:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Mostly clear, with a low around 68. South wind around 5 mph.

    Low: 68 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 91. South wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 91 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A 20 percent chance of showers after 4am. Partly cloudy, with a low around 71. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.

    Low: 71 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Columbus Day

    Columbus Day: A slight chance of showers, with thunderstorms also possible after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 92. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    High: 92 °F

    Slight Chance
    Showers then
    Slight Chance
    T-storms

  • Monday Night

    Monday Night: Partly cloudy, with a low around 75. South wind around 5 mph.

    Low: 75 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 93. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 93 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 75. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 93. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 93 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 74. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.

    Low: 74 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 68. South wind around 5 mph.
Sunday
Mostly sunny, with a high near 91. South wind 5 to 15 mph, with gusts as high as 25 mph.
Sunday Night
A 20 percent chance of showers after 4am. Partly cloudy, with a low around 71. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.
Columbus Day
A slight chance of showers, with thunderstorms also possible after 4pm. Cloudy, then gradually becoming mostly sunny, with a high near 92. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Monday Night
Partly cloudy, with a low around 75. South wind around 5 mph.
Tuesday
Partly sunny, with a high near 93. South wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday Night
Partly cloudy, with a low around 75. South southeast wind around 10 mph, with gusts as high as 20 mph.
Wednesday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 93. South wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 74. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.
Thursday
A 40 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 89.
Thursday Night
A 20 percent chance of showers. Partly cloudy, with a low around 69.
Friday
A 20 percent chance of showers. Mostly sunny, with a high near 84.
Friday Night
Mostly cloudy, with a low around 64.
Saturday
Mostly sunny, with a high near 78.
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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:
7:44 pm CDT Oct 10, 2026
Forecast Valid:
10pm CDT Oct 10, 2026-6pm CDT Oct 17, 2026
 
Forecast Discussion
 
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Additional Resources

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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