Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Mostly Cloudy

69°F

21°C

Humidity 96%
Wind Speed S 5 mph
Barometer 29.86 in (1010.4 mb)
Dewpoint 68°F (20°C)
Visibility 10.00 mi
Last update 18 Apr 7:56 am CDT
Extended Forecast for

San Marcos TX

  • Today

    Today: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4pm.  Cloudy, with a temperature rising to near 73 by 10am, then falling to around 62 during the remainder of the day. Southwest wind 10 to 15 mph becoming north 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph.  Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 73 °F

    Showers
    Likely

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly before 1am.  Mostly cloudy, with a low around 53. North wind 15 to 20 mph, with gusts as high as 35 mph.  Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 53 °F

    Showers
    Likely

  • Sunday

    Sunday: Partly sunny, with a high near 71. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 71 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 55. East wind around 5 mph becoming calm  in the evening.

    Low: 55 °F

    Mostly Cloudy

  • Monday

    Monday: A 50 percent chance of showers and thunderstorms.  Cloudy, with a high near 67. East northeast wind around 5 mph.

    High: 67 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A 50 percent chance of showers and thunderstorms.  Cloudy, with a low around 57. East wind around 5 mph becoming calm  in the evening.

    Low: 57 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms.  Cloudy, with a high near 71. East wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 71 °F

    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms before 1am.  Mostly cloudy, with a low around 63. Southeast wind 5 to 10 mph.

    Low: 63 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms, mainly after 1pm.  Mostly cloudy, with a high near 81. Southeast wind 5 to 10 mph.

    High: 81 °F

    Chance
    T-storms

Detailed Forecast

Today
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 4pm. Cloudy, with a temperature rising to near 73 by 10am, then falling to around 62 during the remainder of the day. Southwest wind 10 to 15 mph becoming north 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
Showers and thunderstorms likely, mainly before 1am. Mostly cloudy, with a low around 53. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday
Partly sunny, with a high near 71. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Mostly cloudy, with a low around 55. East wind around 5 mph becoming calm in the evening.
Monday
A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 67. East northeast wind around 5 mph.
Monday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 57. East wind around 5 mph becoming calm in the evening.
Tuesday
A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 71. East 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 63. Southeast wind 5 to 10 mph.
Wednesday
A 30 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 81. Southeast wind 5 to 10 mph.
Wednesday Night
Mostly cloudy, with a low around 67.
Thursday
Mostly cloudy, with a high near 85.
Thursday Night
Mostly cloudy, with a low around 68.
Friday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.91°W (Elev. 597 ft)
7:34 am CDT Apr 18, 2026
8am CDT Apr 18, 2026-6pm CDT Apr 24, 2026
 
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Additional Resources

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Hourly Weather Forecast

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