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.

A Few Clouds

73°F

23°C

Humidity 94%
Wind Speed S 8 mph
Barometer 29.73 in (1006.1 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Last update 25 Apr 1:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Patchy fog after 3am. Otherwise, mostly cloudy, with a low around 70. South southwest wind around 5 mph.

    Low: 70 °F

    Patchy Fog

  • Saturday

    Saturday: Patchy fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 90. South wind 5 to 10 mph.

    High: 90 °F

    Patchy Fog
    then Mostly
    Sunny

  • Saturday Night

    Saturday Night: A 20 percent chance of showers and thunderstorms before 10pm. Increasing clouds, with a low around 69. South southwest wind around 5 mph.

    Low: 69 °F

    Slight Chance
    T-storms then
    Mostly Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 91. South wind 5 to 10 mph.

    High: 91 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 71. South southeast wind around 10 mph.

    Low: 71 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 93. South wind 5 to 10 mph.

    High: 93 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 72. South southeast wind 5 to 10 mph.

    Low: 72 °F

    Mostly 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: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. South southeast wind 5 to 10 mph.

    Low: 70 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
Patchy fog after 3am. Otherwise, mostly cloudy, with a low around 70. South southwest wind around 5 mph.
Saturday
Patchy fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 90. South wind 5 to 10 mph.
Saturday Night
A 20 percent chance of showers and thunderstorms before 10pm. Increasing clouds, with a low around 69. South southwest wind around 5 mph.
Sunday
Mostly cloudy, with a high near 91. South wind 5 to 10 mph.
Sunday Night
Mostly cloudy, with a low around 71. South southeast wind around 10 mph.
Monday
Mostly cloudy, with a high near 93. South wind 5 to 10 mph.
Monday Night
Mostly cloudy, with a low around 72. South southeast wind 5 to 10 mph.
Tuesday
Partly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. South southeast wind 5 to 10 mph.
Wednesday
Partly sunny, with a high near 91.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 85.
Thursday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Friday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 78.
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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:
1:24 am CDT Apr 25, 2026
Forecast Valid:
2am CDT Apr 25, 2026-6pm CDT May 1, 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