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.

Mostly Cloudy

85°F

29°C

Humidity 55%
Wind Speed SE 16 G 24 mph
Barometer 29.84 in (1009.6 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index88°F (31°C)
Last update 2 Apr 3:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 85. South southeast wind around 15 mph, with gusts as high as 20 mph.

    High: 85 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A 10 percent chance of showers and thunderstorms before 7pm. Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Slight Chance
    T-storms then
    Cloudy

  • Friday

    Friday: Cloudy, then gradually becoming mostly sunny, with a high near 88. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    High: 88 °F

    Decreasing
    Clouds

  • Friday Night

    Friday Night: A 50 percent chance of showers and thunderstorms. Increasing clouds, with a low around 69. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.

    Low: 69 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers and possibly a thunderstorm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    High: 78 °F

    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 53. North northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.

    Low: 53 °F

    Chance
    Showers

  • Sunday

    Sunday: A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 66. North northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 66 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: A 20 percent chance of showers. Cloudy, with a low around 52. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 52 °F

    Slight Chance
    Showers

  • Monday

    Monday: A 20 percent chance of showers before 1pm. Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.

    High: 70 °F

    Slight Chance
    Showers

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 85. South southeast wind around 15 mph, with gusts as high as 20 mph.
Tonight
A 10 percent chance of showers and thunderstorms before 7pm. Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Friday
Cloudy, then gradually becoming mostly sunny, with a high near 88. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Friday Night
A 50 percent chance of showers and thunderstorms. Increasing clouds, with a low around 69. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.
Saturday
Showers and possibly a thunderstorm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Saturday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 53. North northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.
Sunday
A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 66. North northeast wind around 15 mph, with gusts as high as 25 mph.
Sunday Night
A 20 percent chance of showers. Cloudy, with a low around 52. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday
A 20 percent chance of showers before 1pm. Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.
Monday Night
Partly cloudy, with a low around 48.
Tuesday
Partly sunny, with a high near 73.
Tuesday Night
Mostly cloudy, with a low around 51.
Wednesday
Mostly sunny, with a high near 78.
Wednesday Night
Mostly cloudy, with a low around 59.
Thursday
Mostly cloudy, with a high near 79.
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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:
4:02 pm CDT Apr 2, 2026
Forecast Valid:
4pm CDT Apr 2, 2026-6pm CDT Apr 9, 2026
 
Forecast Discussion
 
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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