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

82°F

28°C

Humidity 60%
Wind Speed S 20 mph
Barometer 29.91 in (1012.0 mb)
Dewpoint 67°F (19°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 17 Apr 11:56 am CDT
Extended Forecast for

3 Miles WNW San Marcos Municipal Airport TX

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 90. South wind around 15 mph, with gusts as high as 30 mph.

    High: 90 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly cloudy, with a low around 65. South southeast wind 5 to 15 mph, with gusts as high as 30 mph.

    Low: 65 °F

    Mostly Cloudy

  • Saturday

    Saturday: A 50 percent chance of showers and thunderstorms. Cloudy, with a temperature rising to near 72 by 10am, then falling to around 62 during the remainder of the day. South wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 30 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 72 °F⇓

    Chance
    Showers then
    Chance
    T-storms

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms between 1am and 4am, then a chance of showers after 4am. Mostly cloudy, with a low around 52. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%.

    Low: 52 °F

    Showers
    Likely

  • Sunday

    Sunday: Partly sunny, with a high near 73. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 73 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 54. East northeast wind 5 to 10 mph becoming light in the evening.

    Low: 54 °F

    Mostly Cloudy

  • Monday

    Monday: A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 67. East northeast wind around 5 mph. Chance of precipitation is 50%.

    High: 67 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57. East wind around 5 mph.

    Low: 57 °F

    Chance
    Showers then
    Chance
    T-storms

  • Tuesday

    Tuesday: A 40 percent chance of showers and thunderstorms. Cloudy, with a high near 74. East southeast wind 5 to 10 mph.

    High: 74 °F

    Chance
    Showers then
    Chance
    T-storms

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 90. South wind around 15 mph, with gusts as high as 30 mph.
Tonight
Mostly cloudy, with a low around 65. South southeast wind 5 to 15 mph, with gusts as high as 30 mph.
Saturday
A 50 percent chance of showers and thunderstorms. Cloudy, with a temperature rising to near 72 by 10am, then falling to around 62 during the remainder of the day. South wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 30 mph. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday Night
Showers likely and possibly a thunderstorm before 1am, then a chance of showers and thunderstorms between 1am and 4am, then a chance of showers after 4am. Mostly cloudy, with a low around 52. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%.
Sunday
Partly sunny, with a high near 73. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Mostly cloudy, with a low around 54. East northeast wind 5 to 10 mph becoming light in the evening.
Monday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 67. East northeast wind around 5 mph. Chance of precipitation is 50%.
Monday Night
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57. East wind around 5 mph.
Tuesday
A 40 percent chance of showers and thunderstorms. Cloudy, with a high near 74. East southeast wind 5 to 10 mph.
Tuesday Night
Mostly cloudy, with a low around 63.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 65.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 84.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
3 Miles WNW San Marcos Municipal Airport TX
 29.93°N 97.91°W (Elev. 738 ft)
Last Update:
11:32 am CDT Apr 17, 2026
Forecast Valid:
12pm CDT Apr 17, 2026-6pm CDT Apr 23, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation