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

54°F

12°C

Humidity 87%
Wind Speed N 15 mph
Barometer 30.08 in (1018.0 mb)
Dewpoint 50°F (10°C)
Visibility 10.00 mi
Wind Chill50°F (10°C)
Last update 8 Mar 1:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: A 30 percent chance of showers after 3am. Mostly cloudy, with a low around 56. North wind around 10 mph.

    Low: 56 °F

    Chance
    Showers

  • Sunday

    Sunday: A 40 percent chance of showers and thunderstorms, mainly before 3pm. Cloudy, with a high near 67. North wind 5 to 10 mph.

    High: 67 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: A 20 percent chance of showers and thunderstorms before 9pm. Patchy fog after midnight. Otherwise, cloudy, with a low around 60. Northeast wind around 5 mph becoming calm in the evening.

    Low: 60 °F

    Slight Chance
    T-storms then
    Patchy Fog

  • Monday

    Monday: A 40 percent chance of showers. Patchy fog before 9am. Otherwise, cloudy, with a high near 82. Light southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph.

    High: 82 °F

    Chance
    Showers and
    Patchy Fog

  • Monday Night

    Monday Night: A 20 percent chance of showers before midnight. Cloudy, with a low around 68. South southeast wind around 10 mph.

    Low: 68 °F

    Slight Chance
    Showers then
    Cloudy

  • Tuesday

    Tuesday: A chance of showers, with thunderstorms also possible after noon. Cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.

    High: 83 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after midnight. Low around 62. South southeast wind 5 to 15 mph becoming west after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%.

    Low: 62 °F

    Chance
    T-storms then
    Showers

  • Wednesday

    Wednesday: A 20 percent chance of showers before noon. Sunny, with a high near 81. West wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph.

    High: 81 °F

    Slight Chance
    Showers then
    Sunny

  • Wednesday Night

    Wednesday Night: Clear, with a low around 47. North wind around 15 mph, with gusts as high as 25 mph.

    Low: 47 °F

    Clear

Detailed Forecast

Overnight
A 30 percent chance of showers after 3am. Mostly cloudy, with a low around 56. North wind around 10 mph.
Sunday
A 40 percent chance of showers and thunderstorms, mainly before 3pm. Cloudy, with a high near 67. North wind 5 to 10 mph.
Sunday Night
A 20 percent chance of showers and thunderstorms before 9pm. Patchy fog after midnight. Otherwise, cloudy, with a low around 60. Northeast wind around 5 mph becoming calm in the evening.
Monday
A 40 percent chance of showers. Patchy fog before 9am. Otherwise, cloudy, with a high near 82. Light southeast wind becoming south 5 to 10 mph in the morning. Winds could gust as high as 20 mph.
Monday Night
A 20 percent chance of showers before midnight. Cloudy, with a low around 68. South southeast wind around 10 mph.
Tuesday
A chance of showers, with thunderstorms also possible after noon. Cloudy, with a high near 83. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 40%.
Tuesday Night
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after midnight. Low around 62. South southeast wind 5 to 15 mph becoming west after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%.
Wednesday
A 20 percent chance of showers before noon. Sunny, with a high near 81. West wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph.
Wednesday Night
Clear, with a low around 47. North wind around 15 mph, with gusts as high as 25 mph.
Thursday
Sunny, with a high near 69.
Thursday Night
Clear, with a low around 45.
Friday
Sunny, with a high near 80.
Friday Night
Mostly clear, with a low around 54.
Saturday
Sunny, with a high near 86.
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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:
12:44 am CST Mar 8, 2026
Forecast Valid:
1am CST Mar 8, 2026-6pm CDT Mar 14, 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