National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Mostly Cloudy and Breezy

74°F

23°C

Humidity 28%
Wind Speed N 21 G 29 mph
Barometer 30.12 in (1019.4 mb)
Dewpoint 39°F (4°C)
Visibility 10.00 mi
Last update 21 Feb 2:56 pm CST
Extended Forecast for

San Marcos TX

Red Flag Warning until February 21, 09:00pm
Click here for hazard details and duration
Red Flag Warning
  •  
    Red Flag Warning until February 21, 09:00pm

    NOW until 9:00pm Sat

    Red Flag Warning

  • This Afternoon

    High: 69 °F

    Mostly Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 41. North wind 15 to 20 mph, with gusts as high as 30 mph.

    Low: 41 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 64. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 64 °F

    Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 36. North northeast wind 5 to 10 mph.

    Low: 36 °F

    Partly Cloudy

  • Monday

    Monday: Sunny, with a high near 64. North northeast wind around 5 mph becoming east southeast in the afternoon.

    High: 64 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 38. East southeast wind around 5 mph becoming southwest after midnight.

    Low: 38 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 73. South southwest wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 73 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 54. South wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 54 °F

    Partly Cloudy

Detailed Forecast

This Afternoon
Mostly sunny, with a steady temperature around 69. North wind around 20 mph, with gusts as high as 30 mph.
Tonight
Mostly clear, with a low around 41. North wind 15 to 20 mph, with gusts as high as 30 mph.
Sunday
Sunny, with a high near 64. North northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Partly cloudy, with a low around 36. North northeast wind 5 to 10 mph.
Monday
Sunny, with a high near 64. North northeast wind around 5 mph becoming east southeast in the afternoon.
Monday Night
Mostly clear, with a low around 38. East southeast wind around 5 mph becoming southwest after midnight.
Tuesday
Sunny, with a high near 73. South southwest wind 5 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Partly cloudy, with a low around 54. South wind 10 to 15 mph, with gusts as high as 20 mph.
Wednesday
Mostly sunny, with a high near 84. South southwest wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 58.
Thursday
Sunny, with a high near 84.
Thursday Night
Mostly clear, with a low around 51.
Friday
Sunny, with a high near 79.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
1:44 pm CST Feb 21, 2026
Forecast Valid:
3pm CST Feb 21, 2026-6pm CST Feb 27, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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