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

72°F

22°C

Humidity 84%
Wind Speed SE 16 mph
Barometer 30.07 in (1017.5 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Last update 12 Apr 12:56 am CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Overnight

    Overnight: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 68 °F

    Chance
    Showers

  • Sunday

    Sunday: A chance of showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and 1pm, then showers and thunderstorms likely after 1pm. Cloudy, with a high near 79. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    High: 79 °F

    Showers
    Likely then
    T-storms
    Likely

  • Sunday Night

    Sunday Night: A 40 percent chance of showers and thunderstorms before 1am. Cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 69 °F

    Chance
    T-storms

  • Monday

    Monday: A 30 percent chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 9am. Otherwise, mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 84 °F

    Patchy Fog
    then Chance
    T-storms

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 84 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 67 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 84 °F

    Cloudy then
    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Slight Chance
    T-storms

Detailed Forecast

Overnight
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
A chance of showers and thunderstorms before 10am, then showers likely and possibly a thunderstorm between 10am and 1pm, then showers and thunderstorms likely after 1pm. Cloudy, with a high near 79. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Sunday Night
A 40 percent chance of showers and thunderstorms before 1am. Cloudy, with a low around 69. South southeast wind around 10 mph, with gusts as high as 20 mph.
Monday
A 30 percent chance of showers and thunderstorms after 1pm. Patchy fog between 8am and 9am. Otherwise, mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 67. South southeast wind around 10 mph, with gusts as high as 20 mph.
Tuesday
Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind 10 to 15 mph, with gusts as high as 20 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 67. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday
Partly sunny, with a high near 88.
Thursday Night
Partly cloudy, with a low around 68.
Friday
Mostly cloudy, with a high near 89.
Friday Night
Mostly cloudy, with a low around 69.
Saturday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos Municipal Airport TX
 29.88°N 97.86°W (Elev. 600 ft)
Last Update:
1:44 am CDT Apr 12, 2026
Forecast Valid:
1am CDT Apr 12, 2026-6pm CDT Apr 18, 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