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

74°F

23°C

Humidity 94%
Wind Speed S 16 mph
Barometer 30.03 in (1016.0 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 28 Apr 12:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Cloudy, with a low around 70. South wind around 10 mph.

    Low: 70 °F

    Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 88. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 88 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 69 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 87 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 71. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 71 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 87. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 70%.

    High: 87 °F

    Chance
    T-storms then
    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. South wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Chance
    T-storms

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. South wind 5 to 10 mph.

    High: 92 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 67. South wind 5 to 10 mph.

    Low: 67 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
Cloudy, with a low around 70. South wind around 10 mph.
Monday
Mostly cloudy, with a high near 88. South wind 10 to 15 mph, with gusts as high as 25 mph.
Monday Night
Increasing clouds, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Tuesday
Mostly cloudy, with a high near 87. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
A 20 percent chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 71. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Wednesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Mostly cloudy, with a high near 87. South wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 70%.
Wednesday Night
A 30 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 69. South wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. South wind 5 to 10 mph.
Thursday Night
A 20 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 67. South wind 5 to 10 mph.
Friday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. Partly sunny, with a high near 87.
Friday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 65.
Saturday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 84.
Saturday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 66.
Sunday
A 30 percent chance of showers and thunderstorms. Partly sunny, with a high near 85.
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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:
12:12 am CDT Apr 28, 2025
Forecast Valid:
1am CDT Apr 28, 2025-6pm CDT May 4, 2025
 
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