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.

Fair

76°F

24°C

Humidity 72%
Wind Speed SE 14 mph
Barometer 29.90 in (1011.8 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 3 Apr 7:56 pm CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Tonight

    Tonight: A 40 percent chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 69 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1pm. High near 79. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 79 °F

    Showers

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 52. North wind 10 to 15 mph, with gusts 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.

    Low: 52 °F

    Showers
    Likely then
    Chance
    Showers

  • Sunday

    Sunday: A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 65. North northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 65 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: A 30 percent chance of showers, mainly before 1am. Cloudy, with a low around 53. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 53 °F

    Chance
    Showers

  • Monday

    Monday: Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.

    High: 70 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 49. East northeast wind around 5 mph becoming calm in the evening.

    Low: 49 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 69. East wind around 5 mph.

    High: 69 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 51. East wind around 5 mph becoming calm in the evening.

    Low: 51 °F

    Mostly Cloudy

Detailed Forecast

Tonight
A 40 percent chance of showers and thunderstorms after 10pm. Mostly cloudy, with a low around 69. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Saturday
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1pm. High near 79. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Saturday Night
Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 52. North wind 10 to 15 mph, with gusts 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.
Sunday
A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 65. North northeast wind around 15 mph, with gusts as high as 25 mph.
Sunday Night
A 30 percent chance of showers, mainly before 1am. Cloudy, with a low around 53. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday
Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.
Monday Night
Mostly cloudy, with a low around 49. East northeast wind around 5 mph becoming calm in the evening.
Tuesday
Mostly cloudy, with a high near 69. East wind around 5 mph.
Tuesday Night
Mostly cloudy, with a low around 51. East wind around 5 mph becoming calm in the evening.
Wednesday
Mostly sunny, with a high near 78.
Wednesday Night
Mostly cloudy, with a low around 58.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81.
Thursday Night
Mostly cloudy, with a low around 63.
Friday
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 83.
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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:
6:46 pm CDT Apr 3, 2026
Forecast Valid:
8pm CDT Apr 3, 2026-6pm CDT Apr 10, 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