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

67°F

19°C

Humidity 42%
Wind Speed NE 20 mph
Barometer 30.33 in (1026.6 mb)
Dewpoint 43°F (6°C)
Visibility 10.00 mi
Last update 6 Apr 11:56 am CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: Sunny, with a high near 73. Northeast wind around 10 mph, with gusts as high as 20 mph.

    High: 73 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 48. East northeast wind around 5 mph becoming calm in the evening.

    Low: 48 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 76. North wind around 5 mph becoming east southeast in the afternoon.

    High: 76 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 53. East wind around 5 mph becoming calm after midnight.

    Low: 53 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 78. Calm wind becoming southeast around 5 mph in the morning.

    High: 78 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 61. Southeast wind around 5 mph.

    Low: 61 °F

    Mostly Cloudy

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 82. Light southeast wind increasing to 5 to 10 mph in the morning.

    High: 82 °F

    Mostly Cloudy
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Southeast wind 5 to 10 mph.

    Low: 64 °F

    Slight Chance
    T-storms

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 80. Southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 80 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
Sunny, with a high near 73. Northeast wind around 10 mph, with gusts as high as 20 mph.
Tonight
Partly cloudy, with a low around 48. East northeast wind around 5 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 76. North wind around 5 mph becoming east southeast in the afternoon.
Tuesday Night
Partly cloudy, with a low around 53. East wind around 5 mph becoming calm after midnight.
Wednesday
Partly sunny, with a high near 78. Calm wind becoming southeast around 5 mph in the morning.
Wednesday Night
Mostly cloudy, with a low around 61. Southeast wind around 5 mph.
Thursday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 82. Light southeast wind increasing to 5 to 10 mph in the morning.
Thursday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Southeast wind 5 to 10 mph.
Friday
A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 80. Southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 65.
Saturday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 80.
Saturday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 68.
Sunday
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 82.
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:
12:30 pm CDT Apr 6, 2026
Forecast Valid:
12pm CDT Apr 6, 2026-6pm CDT Apr 12, 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