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

54°F

12°C

Humidity 72%
Wind Speed N 5 mph
Barometer 30.20 in (1022.4 mb)
Dewpoint 45°F (7°C)
Visibility 10.00 mi
Wind Chill53°F (12°C)
Last update 12 Feb 12:56 am CST
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Mostly clear, with a low around 52. Calm wind.

    Low: 52 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 80. Calm wind becoming south around 5 mph in the afternoon.

    High: 80 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 60. South southeast wind around 5 mph.

    Low: 60 °F

    Partly Cloudy

  • Friday

    Friday: Mostly cloudy, with a high near 81. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Mostly Cloudy

  • Friday Night

    Friday Night: A 50 percent chance of showers after midnight. Mostly cloudy, with a low around 63. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 63 °F

    Mostly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: Showers, with thunderstorms also possible after 9am. High near 79. South southeast wind around 10 mph becoming west in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 100%.

    High: 79 °F

    Showers

  • Saturday Night

    Saturday Night: A 20 percent chance of showers before midnight. Mostly clear, with a low around 56. West wind 5 to 10 mph becoming north northwest after midnight. Winds could gust as high as 20 mph.

    Low: 56 °F

    Slight Chance
    Showers then
    Clear

  • Sunday

    Sunday: Sunny, with a high near 77. North northwest wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 77 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 47. North wind around 5 mph becoming calm in the evening.

    Low: 47 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 52. Calm wind.
Thursday
Mostly sunny, with a high near 80. Calm wind becoming south around 5 mph in the afternoon.
Thursday Night
Partly cloudy, with a low around 60. South southeast wind around 5 mph.
Friday
Mostly cloudy, with a high near 81. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
A 50 percent chance of showers after midnight. Mostly cloudy, with a low around 63. South southeast wind around 10 mph, with gusts as high as 20 mph.
Saturday
Showers, with thunderstorms also possible after 9am. High near 79. South southeast wind around 10 mph becoming west in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 100%.
Saturday Night
A 20 percent chance of showers before midnight. Mostly clear, with a low around 56. West wind 5 to 10 mph becoming north northwest after midnight. Winds could gust as high as 20 mph.
Sunday
Sunny, with a high near 77. North northwest wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Mostly clear, with a low around 47. North wind around 5 mph becoming calm in the evening.
Washington's Birthday
Sunny, with a high near 78.
Monday Night
Partly cloudy, with a low around 51.
Tuesday
Mostly sunny, with a high near 83.
Tuesday Night
Partly cloudy, with a low around 58.
Wednesday
Mostly sunny, with a high near 84.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
12:44 am CST Feb 12, 2026
Forecast Valid:
1am CST Feb 12, 2026-6pm CST Feb 18, 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