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.

Overcast

79°F

26°C

Humidity 82%
Wind Speed S 18 mph
Barometer 29.99 in (1014.9 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 14 Oct 11:56 pm CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Partly cloudy, with a low around 69. South southeast wind 5 to 10 mph.

    Low: 69 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 89. South southeast wind around 5 mph.

    High: 89 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A 30 percent chance of showers, mainly after 4am. Partly cloudy, with a low around 66. Calm wind becoming north around 5 mph after midnight.

    Low: 66 °F

    Partly Cloudy
    then Chance
    Showers

  • Friday

    Friday: A 30 percent chance of showers before 7am. Partly sunny, with a high near 73. Breezy, with a north wind 20 to 25 mph, with gusts as high as 40 mph.

    High: 73 °F

    Chance
    Showers then
    Partly Sunny
    and Breezy

  • Friday Night

    Friday Night: Partly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 40 mph.

    Low: 51 °F

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 69. North wind 10 to 20 mph, with gusts as high as 30 mph.

    High: 69 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 50. North northeast wind around 5 mph becoming calm.

    Low: 50 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 74. North wind around 5 mph becoming east northeast in the afternoon.

    High: 74 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 53. Calm wind.

    Low: 53 °F

    Mostly Clear

Detailed Forecast

Overnight
Partly cloudy, with a low around 69. South southeast wind 5 to 10 mph.
Thursday
Mostly sunny, with a high near 89. South southeast wind around 5 mph.
Thursday Night
A 30 percent chance of showers, mainly after 4am. Partly cloudy, with a low around 66. Calm wind becoming north around 5 mph after midnight.
Friday
A 30 percent chance of showers before 7am. Partly sunny, with a high near 73. Breezy, with a north wind 20 to 25 mph, with gusts as high as 40 mph.
Friday Night
Partly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 40 mph.
Saturday
Sunny, with a high near 69. North wind 10 to 20 mph, with gusts as high as 30 mph.
Saturday Night
Mostly clear, with a low around 50. North northeast wind around 5 mph becoming calm.
Sunday
Sunny, with a high near 74. North wind around 5 mph becoming east northeast in the afternoon.
Sunday Night
Mostly clear, with a low around 53. Calm wind.
Monday
Mostly sunny, with a high near 80.
Monday Night
Partly cloudy, with a low around 60.
Tuesday
A 20 percent chance of showers. Partly sunny, with a high near 82.
Tuesday Night
Partly cloudy, with a low around 66.
Wednesday
A 30 percent chance of showers. Mostly sunny, with a high near 87.
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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:
11:33 pm CDT Oct 14, 2026
Forecast Valid:
12am 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