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 with Haze

91°F

33°C

Humidity 57%
Wind Speed S 13 mph
Barometer 29.85 in (1010.0 mb)
Dewpoint 74°F (23°C)
Visibility 4.00 mi
Heat Index100°F (38°C)
Last update 28 Apr 3:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Partly cloudy, with a low around 72. South southeast wind 5 to 10 mph.

    Low: 72 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 88. East southeast wind around 5 mph becoming north northeast in the afternoon.

    High: 88 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 67. Northeast wind 5 to 10 mph.

    Low: 67 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms. Cloudy, with a high near 81. East wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Cloudy, with a low around 64. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.

    Low: 64 °F

    Chance
    T-storms then
    Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 72. Northeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%.

    High: 72 °F

    Showers then
    T-storms

  • Friday Night

    Friday Night: A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 53. North wind 15 to 20 mph, with gusts as high as 35 mph.

    Low: 53 °F

    Chance
    T-storms

  • Saturday

    Saturday: Partly sunny, with a high near 69. North northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 69 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 50. North northeast wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 20 mph.

    Low: 50 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 72. South southeast wind 5 to 10 mph.
Wednesday
A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 88. East southeast wind around 5 mph becoming north northeast in the afternoon.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 67. Northeast wind 5 to 10 mph.
Thursday
A 30 percent chance of showers and thunderstorms. Cloudy, with a high near 81. East wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Cloudy, with a low around 64. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%.
Friday
Showers and possibly a thunderstorm. High near 72. Northeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%.
Friday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 53. North wind 15 to 20 mph, with gusts as high as 35 mph.
Saturday
Partly sunny, with a high near 69. North northeast wind around 15 mph, with gusts as high as 25 mph.
Saturday Night
Mostly clear, with a low around 50. North northeast wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 20 mph.
Sunday
Sunny, with a high near 75.
Sunday Night
Mostly cloudy, with a low around 54.
Monday
Mostly sunny, with a high near 82.
Monday Night
Mostly cloudy, with a low around 61.
Tuesday
Mostly cloudy, 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:
3:32 pm CDT Apr 28, 2026
Forecast Valid:
4pm CDT Apr 28, 2026-6pm CDT May 5, 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