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

75°F

24°C

Humidity 60%
Wind Speed SE 8 mph
Barometer 29.98 in (1014.9 mb)
Dewpoint 60°F (16°C)
Visibility 10.00 mi
Last update 10 Oct 8:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Mostly clear, with a low around 68. Calm wind becoming south around 5 mph.

    Low: 68 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 92. South wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 92 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A 20 percent chance of showers after 4am. Partly cloudy, with a low around 70. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.

    Low: 70 °F

    Partly Cloudy
    then Slight
    Chance
    Showers

  • Columbus Day

    Columbus Day: A slight chance of showers before 7am, then a slight chance of showers after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 93. Heat index values as high as 101. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    High: 93 °F

    Slight Chance
    Showers

  • Monday Night

    Monday Night: Partly cloudy, with a low around 74. South wind around 5 mph, with gusts as high as 20 mph.

    Low: 74 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 94 °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 25 mph.

    Low: 75 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 94. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 94 °F

    Mostly Cloudy
    then 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. Calm wind becoming south around 5 mph.
Sunday
Mostly sunny, with a high near 92. 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 70. South southeast wind 5 to 10 mph, with gusts as high as 25 mph.
Columbus Day
A slight chance of showers before 7am, then a slight chance of showers after 1pm. Cloudy, then gradually becoming mostly sunny, with a high near 93. Heat index values as high as 101. 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 74. South wind around 5 mph, with gusts as high as 20 mph.
Tuesday
Partly sunny, with a high near 94. 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 25 mph.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 94. 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 90.
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 85.
Friday Night
Mostly cloudy, with a low around 63.
Saturday
Mostly sunny, with a high near 79.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.9°N 97.91°W (Elev. 640 ft)
Last Update:
7:44 pm CDT Oct 10, 2026
Forecast Valid:
9pm CDT Oct 10, 2026-6pm CDT Oct 17, 2026
 
Forecast Discussion
 
Get as KML Get as XML

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

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