Prolonged Extreme Cold; Eastern U.S. Winter Storm

Another Arctic blast will surge south across the northern Plains tonight, crossing the Midwest and reaching the Gulf Coast Friday night. Dangerously cold temperatures will persist across the eastern U.S. into early February. There is increasing confidence for significant heavy snow across much of the Southern Appalachians, Carolinas, and southern Mid-Atlantic Friday into Sunday. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

71°F

22°C

Humidity 35%
Wind Speed W 9 mph
Barometer 30.04 in (1017.4 mb)
Dewpoint 42°F (6°C)
Visibility 10.00 mi
Last update 29 Jan 4:56 pm CST
Extended Forecast for

San Marcos TX

Cold Weather Advisory January 31, 03:00am until January 31, 10:00am
Click here for hazard details and duration
Cold Weather Advisory
  • Tonight

    Tonight: Mostly cloudy, with a low around 37. North wind 5 to 15 mph, with gusts as high as 20 mph.

    Low: 37 °F

    Mostly Cloudy

  • Friday

    Friday: Mostly cloudy, then gradual clearing during the afternoon, with a high near 56. North wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 56 °F

    Becoming
    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 43. North northeast wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 43 °F

    Sunny

  • Saturday Night

    Saturday Night: Clear, with a low around 22. Northeast wind around 5 mph becoming calm  in the evening.

    Low: 22 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 55. Calm wind becoming south around 5 mph in the afternoon.

    High: 55 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 36. South southwest wind around 5 mph becoming west after midnight.

    Low: 36 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 63. West wind around 5 mph becoming south southeast in the afternoon.

    High: 63 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 51. South southeast wind around 5 mph.

    Low: 51 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Mostly cloudy, with a low around 37. North wind 5 to 15 mph, with gusts as high as 20 mph.
Friday
Mostly cloudy, then gradual clearing during the afternoon, 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 43. North northeast wind 5 to 15 mph, with gusts as high as 25 mph.
Saturday Night
Clear, with a low around 22. Northeast wind around 5 mph becoming calm in the evening.
Sunday
Sunny, with a high near 55. Calm wind becoming south around 5 mph in the afternoon.
Sunday Night
Mostly clear, with a low around 36. South southwest wind around 5 mph becoming west after midnight.
Monday
Mostly sunny, with a high near 63. West wind around 5 mph becoming south southeast in the afternoon.
Monday Night
Mostly cloudy, with a low around 51. South southeast wind around 5 mph.
Tuesday
Mostly cloudy, with a high near 71.
Tuesday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 50.
Wednesday
A 30 percent chance of showers. Mostly cloudy, with a high near 63.
Wednesday Night
A 20 percent chance of showers. Partly cloudy, with a low around 40.
Thursday
Mostly sunny, with a high near 60.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
4:32 pm CST Jan 29, 2026
5pm CST Jan 29, 2026-6pm CST Feb 5, 2026
 
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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