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.

Partly Cloudy

81°F

27°C

Humidity 65%
Wind Speed S 12 mph
Barometer 30.07 in (1017.5 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 15 Oct 10:56 am CDT
Extended Forecast for

San Marcos TX

  • Today

    Today: Mostly sunny, with a high near 90. Southeast wind around 5 mph.

    High: 90 °F

    Mostly Sunny

  • Tonight

    Tonight: A 50 percent chance of showers, mainly after 4am. Increasing clouds, with a low around 64. Light and variable wind becoming north 10 to 15 mph after midnight. Winds could gust as high as 20 mph. New precipitation amounts of less than a tenth of an inch possible.

    Low: 64 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: A 30 percent chance of showers before 7am. Partly sunny, with a high near 71. Breezy, with a north wind 20 to 25 mph, with gusts as high as 40 mph.

    High: 71 °F

    Breezy.
    Chance
    Showers then
    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 49. North wind 15 to 20 mph, with gusts as high as 40 mph.

    Low: 49 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 69. North northeast wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 69 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 47. North northeast wind around 5 mph.

    Low: 47 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 72. North wind around 5 mph becoming calm in the afternoon.

    High: 72 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 52. Calm wind.

    Low: 52 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 77. Calm wind becoming east around 5 mph.

    High: 77 °F

    Mostly Sunny

Detailed Forecast

Today
Mostly sunny, with a high near 90. Southeast wind around 5 mph.
Tonight
A 50 percent chance of showers, mainly after 4am. Increasing clouds, with a low around 64. Light and variable wind becoming north 10 to 15 mph after midnight. Winds could gust as high as 20 mph. New precipitation amounts of less than a tenth of an inch possible.
Friday
A 30 percent chance of showers before 7am. Partly sunny, with a high near 71. Breezy, with a north wind 20 to 25 mph, with gusts as high as 40 mph.
Friday Night
Mostly clear, with a low around 49. North wind 15 to 20 mph, with gusts as high as 40 mph.
Saturday
Sunny, with a high near 69. North northeast wind 10 to 15 mph, with gusts as high as 30 mph.
Saturday Night
Mostly clear, with a low around 47. North northeast wind around 5 mph.
Sunday
Sunny, with a high near 72. North wind around 5 mph becoming calm in the afternoon.
Sunday Night
Mostly clear, with a low around 52. Calm wind.
Monday
Mostly sunny, with a high near 77. Calm wind becoming east around 5 mph.
Monday Night
Partly cloudy, with a low around 57.
Tuesday
Mostly sunny, with a high near 82.
Tuesday Night
Partly cloudy, with a low around 61.
Wednesday
Mostly sunny, with a high near 86.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
6:46 am CDT Oct 15, 2026
Forecast Valid:
10am CDT Oct 15, 2026-6pm CDT Oct 21, 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