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

85°F

29°C

Humidity 29%
Wind Speed S 13 mph
Barometer 29.91 in (1012.4 mb)
Dewpoint 49°F (9°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 28 Feb 4:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Patchy fog after 3am. Otherwise, increasing clouds, with a low around 60. South wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 60 °F

    Clear then
    Patchy Fog

  • Sunday

    Sunday: Patchy fog before 8am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 83. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 83 °F

    Patchy Fog
    then Mostly
    Sunny

  • Sunday Night

    Sunday Night: Increasing clouds, with a low around 61. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Low: 61 °F

    Increasing
    Clouds

  • Monday

    Monday: Cloudy through mid morning, then gradual clearing, with a high near 83. South wind 5 to 15 mph, with gusts as high as 20 mph.

    High: 83 °F

    Gradual
    Clearing

  • Monday Night

    Monday Night: Partly cloudy, with a low around 63. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 63 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 87. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 87 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 66 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.

    High: 84 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 66 °F

    Chance
    Showers

Detailed Forecast

Tonight
Patchy fog after 3am. Otherwise, increasing clouds, with a low around 60. South wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday
Patchy fog before 8am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 83. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Increasing clouds, with a low around 61. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Monday
Cloudy through mid morning, then gradual clearing, with a high near 83. South wind 5 to 15 mph, with gusts as high as 20 mph.
Monday Night
Partly cloudy, with a low around 63. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Tuesday
Partly sunny, with a high near 87. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
A 20 percent chance of showers after midnight. Mostly cloudy, with a low around 66. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
A chance of showers, with thunderstorms also possible after noon. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.
Wednesday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66. South southeast wind around 10 mph, with gusts as high as 20 mph.
Thursday
A 30 percent chance of showers, mainly before noon. Partly sunny, with a high near 86.
Thursday Night
Mostly cloudy, with a low around 65.
Friday
A 30 percent chance of showers. Mostly cloudy, with a high near 85.
Friday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 65.
Saturday
Showers likely. Mostly cloudy, with a high near 81. Chance of precipitation is 60%.
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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:
4:44 pm CST Feb 28, 2026
Forecast Valid:
5pm CST Feb 28, 2026-6pm CST Mar 7, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation