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

Late January Extreme Cold; Watching East Coast Storm Threat This Weekend

The next blast of Arctic air surges south down the Plains, across the Great Lakes and through the Southeast and East Friday through Saturday. This could be longest duration of cold in several decades. Forecast models are being closely monitored for potential of another significant winter storm to impact the eastern United States this coming weekend. Confidence in coastal impacts has increased. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

59°F

15°C

Humidity 39%
Wind Speed Vrbl 7 mph
Barometer 30.35 in (1027.9 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Last update 28 Jan 3:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Partly cloudy, with a low around 32. Calm wind.

    Low: 32 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 67. Southwest wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 67 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 36. West northwest wind 5 to 15 mph becoming north after midnight. Winds could gust as high as 20 mph.

    Low: 36 °F

    Mostly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 56. North wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 56 °F

    Partly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 30. North wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 30 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 44. North northeast wind 5 to 15 mph, with gusts as high as 20 mph.

    High: 44 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 21. Northeast wind around 5 mph becoming calm in the evening.

    Low: 21 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 51. Calm wind becoming south around 5 mph in the morning.

    High: 51 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 33. South wind around 5 mph becoming west southwest after midnight.

    Low: 33 °F

    Mostly Clear

Detailed Forecast

Tonight
Partly cloudy, with a low around 32. Calm wind.
Thursday
Mostly sunny, with a high near 67. Southwest wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Mostly cloudy, with a low around 36. West northwest wind 5 to 15 mph becoming north after midnight. Winds could gust as high as 20 mph.
Friday
Partly sunny, with a high near 56. North wind 10 to 15 mph, with gusts as high as 20 mph.
Friday Night
Mostly clear, with a low around 30. North wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday
Sunny, with a high near 44. North northeast wind 5 to 15 mph, with gusts as high as 20 mph.
Saturday Night
Clear, with a low around 21. Northeast wind around 5 mph becoming calm in the evening.
Sunday
Sunny, with a high near 51. Calm wind becoming south around 5 mph in the morning.
Sunday Night
Mostly clear, with a low around 33. South wind around 5 mph becoming west southwest after midnight.
Monday
Mostly sunny, with a high near 62.
Monday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 47.
Tuesday
A 20 percent chance of showers. Mostly cloudy, with a high near 66.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 52.
Wednesday
A 40 percent chance of showers. Mostly cloudy, with a high near 63.
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:
4:33 pm CST Jan 28, 2026
Forecast Valid:
4pm CST Jan 28, 2026-6pm CST Feb 4, 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