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

65°F

18°C

Humidity 90%
Wind Speed N 13 mph
Barometer 29.93 in (1012.8 mb)
Dewpoint 62°F (17°C)
Visibility 10.00 mi
Last update 30 Apr 9:56 am CDT
Extended Forecast for

San Marcos Municipal Airport TX

  • Today

    Today: A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 79. Northeast wind around 10 mph.

    High: 79 °F

    Chance
    T-storms

  • Tonight

    Tonight: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 4am. Low around 61. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 61 °F

    Showers
    Likely then
    Showers

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 65. Northeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

    High: 65 °F

    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers before 1am. Mostly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 30 mph.

    Low: 51 °F

    Chance
    Showers

  • Saturday

    Saturday: Sunny, with a high near 71. North wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 71 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 48. Northeast wind 5 to 10 mph becoming light north northeast in the evening.

    Low: 48 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 75. Calm wind becoming southeast around 5 mph in the afternoon.

    High: 75 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 56. Southeast wind around 5 mph.

    Low: 56 °F

    Mostly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 82. Light south wind increasing to 10 to 15 mph in the morning. Winds could gust as high as 20 mph.

    High: 82 °F

    Partly Sunny

Detailed Forecast

Today
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 79. Northeast wind around 10 mph.
Tonight
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 4am. Low around 61. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Friday
Showers and possibly a thunderstorm. High near 65. Northeast wind 10 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Friday Night
A 30 percent chance of showers before 1am. Mostly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 30 mph.
Saturday
Sunny, with a high near 71. North wind 10 to 15 mph, with gusts as high as 25 mph.
Saturday Night
Mostly clear, with a low around 48. Northeast wind 5 to 10 mph becoming light north northeast in the evening.
Sunday
Mostly sunny, with a high near 75. Calm wind becoming southeast around 5 mph in the afternoon.
Sunday Night
Mostly cloudy, with a low around 56. Southeast wind around 5 mph.
Monday
Partly sunny, with a high near 82. Light south wind increasing to 10 to 15 mph in the morning. Winds could gust as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 65.
Tuesday
Mostly cloudy, with a high near 89.
Tuesday Night
Mostly cloudy, with a low around 70.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 89.
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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:
6:44 am CDT Apr 30, 2026
Forecast Valid:
10am CDT Apr 30, 2026-6pm CDT May 6, 2026
 
Forecast Discussion
 
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Additional Resources

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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