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 and Breezy

86°F

30°C

Humidity 51%
Wind Speed S 22 G 30 mph
Barometer 29.87 in (1010.5 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index88°F (31°C)
Last update 17 Apr 1:56 pm CDT
Extended Forecast for

4 Miles SSW San Marcos TX

  • This Afternoon

    This Afternoon: Partly sunny, with a high near 89. South wind around 15 mph, with gusts as high as 30 mph.

    High: 89 °F

    Partly Sunny

  • Tonight

    Tonight: Mostly cloudy, with a low around 66. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.

    Low: 66 °F

    Mostly Cloudy

  • Saturday

    Saturday: A 50 percent chance of showers and thunderstorms, mainly after 1pm. 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 10 mph becoming north 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 72 °F⇓

    Slight Chance
    T-storms 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. Cloudy, with a low around 54. North northeast wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 70%.

    Low: 54 °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 55. East northeast wind 5 to 10 mph becoming light in the evening.

    Low: 55 °F

    Mostly Cloudy

  • Monday

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

    High: 67 °F

    Chance
    Showers then
    Chance
    T-storms

  • Monday Night

    Monday Night: A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 58. East wind around 5 mph.

    Low: 58 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 72. East southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 72 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
Partly sunny, with a high near 89. South wind around 15 mph, with gusts as high as 30 mph.
Tonight
Mostly cloudy, with a low around 66. South southeast wind 10 to 20 mph, with gusts as high as 30 mph.
Saturday
A 50 percent chance of showers and thunderstorms, mainly after 1pm. 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 10 mph becoming north 15 to 20 mph in the afternoon. Winds could gust as high as 30 mph. New rainfall amounts of less than a tenth 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. Cloudy, with a low around 54. North northeast wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 70%.
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 55. East northeast wind 5 to 10 mph becoming light in the evening.
Monday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 67. East wind around 5 mph.
Monday Night
A 40 percent chance of showers and thunderstorms. Cloudy, with a low around 58. East wind around 5 mph.
Tuesday
A 50 percent chance of showers and thunderstorms. Cloudy, with a high near 72. East southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday Night
Mostly cloudy, with a low around 64.
Wednesday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82.
Wednesday Night
Mostly cloudy, with a low around 66.
Thursday
Mostly cloudy, with a high near 85.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSW San Marcos TX
 29.83°N 97.94°W (Elev. 610 ft)
Last Update:
1:30 pm CDT Apr 17, 2026
Forecast Valid:
2pm CDT Apr 17, 2026-6pm CDT Apr 23, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation