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

Tracking Winter Weather and Frigid Temperatures This Weekend

Another clipper will drop into the Northern Plains and Upper Midwest into Sunday with snow and gusty winds contributing to some areas of blizzard conditions and snow squalls. Impactful snowfall will occur up and down the East Coast Sunday extending from the western Florida Panhandle to Maine. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

43°F

6°C

Humidity 38%
Wind Speed W 5 mph
Barometer 30.44 in (1031.0 mb)
Dewpoint 19°F (-7°C)
Visibility 10.00 mi
Wind Chill40°F (4°C)
Last update 18 Jan 9:56 am CST
Extended Forecast for

San Marcos TX

  • Today

    Today: Sunny, with a high near 61. Southwest wind 5 to 10 mph.

    High: 61 °F

    Sunny

  • Tonight

    Tonight: Clear, with a low around 34. South southwest wind around 5 mph becoming calm after midnight.

    Low: 34 °F

    Clear

  • M.L.King Day

    M.L.King Day: Sunny, with a high near 64. Light and variable wind becoming east southeast 5 to 10 mph in the afternoon.

    High: 64 °F

    Sunny

  • Monday Night

    Monday Night: Increasing clouds, with a low around 40. North northeast wind around 5 mph.

    Low: 40 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 59. North northeast wind around 5 mph becoming southeast in the afternoon.

    High: 59 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: A 40 percent chance of showers, mainly after midnight. Cloudy, with a low around 51. Southeast wind around 5 mph.

    Low: 51 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A 50 percent chance of showers. Mostly cloudy, with a high near 63. South southeast wind around 5 mph becoming north northwest in the afternoon.

    High: 63 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 50. North wind around 5 mph.

    Low: 50 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 63. North northeast wind around 5 mph becoming east in the afternoon.

    High: 63 °F

    Mostly Sunny

Detailed Forecast

Today
Sunny, with a high near 61. Southwest wind 5 to 10 mph.
Tonight
Clear, with a low around 34. South southwest wind around 5 mph becoming calm after midnight.
M.L.King Day
Sunny, with a high near 64. Light and variable wind becoming east southeast 5 to 10 mph in the afternoon.
Monday Night
Increasing clouds, with a low around 40. North northeast wind around 5 mph.
Tuesday
Mostly cloudy, with a high near 59. North northeast wind around 5 mph becoming southeast in the afternoon.
Tuesday Night
A 40 percent chance of showers, mainly after midnight. Cloudy, with a low around 51. Southeast wind around 5 mph.
Wednesday
A 50 percent chance of showers. Mostly cloudy, with a high near 63. South southeast wind around 5 mph becoming north northwest in the afternoon.
Wednesday Night
Mostly cloudy, with a low around 50. North wind around 5 mph.
Thursday
Mostly sunny, with a high near 63. North northeast wind around 5 mph becoming east in the afternoon.
Thursday Night
Mostly cloudy, with a low around 48.
Friday
Mostly cloudy, with a high near 71.
Friday Night
Mostly cloudy, with a low around 55.
Saturday
Partly sunny, with a high near 73.
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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:
10:32 am CST Jan 18, 2026
Forecast Valid:
11am CST Jan 18, 2026-6pm CST Jan 24, 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