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

Another Arctic Blast in the East; Eastern U.S. Winter Storm

A powerful Arctic blast will bring dangerously cold, record low temperatures to the upper Ohio Valley, Mid-Atlantic, Gulf Coast and Southeast U.S. this weekend. A rapidly deepening storm will produce widespread heavy snow and wind from the southern Appalachians across the Carolinas and southern Virginia into Sunday. Storm-force winds and coastal flooding will be possible along the East Coast. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

40°F

4°C

Humidity 45%
Wind Speed NE 14 mph
Barometer 30.65 in (1038.2 mb)
Dewpoint 20°F (-7°C)
Visibility 10.00 mi
Wind Chill32°F (0°C)
Last update 31 Jan 10:56 am CST
Extended Forecast for

San Marcos TX

  • Today

    Today: Sunny, with a high near 45. North northeast wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 45 °F

    Sunny

  • Tonight

    Tonight: Clear, with a low around 23. Northeast wind around 5 mph becoming calm in the evening.

    Low: 23 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 57. Calm wind becoming south southwest around 5 mph in the afternoon.

    High: 57 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 38. Southwest wind around 5 mph.

    Low: 38 °F

    Mostly Clear

  • Monday

    Monday: Mostly cloudy, with a high near 66. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 66 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 57. South wind around 10 mph.

    Low: 57 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 72. South southwest wind around 10 mph becoming north northwest in the afternoon. Winds could gust as high as 20 mph.

    High: 72 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 45. North wind around 10 mph.

    Low: 45 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 66. North wind around 10 mph, with gusts as high as 20 mph.

    High: 66 °F

    Mostly Sunny

Detailed Forecast

Today
Sunny, with a high near 45. North northeast wind 10 to 15 mph, with gusts as high as 20 mph.
Tonight
Clear, with a low around 23. Northeast wind around 5 mph becoming calm in the evening.
Sunday
Sunny, with a high near 57. Calm wind becoming south southwest around 5 mph in the afternoon.
Sunday Night
Mostly clear, with a low around 38. Southwest wind around 5 mph.
Monday
Mostly cloudy, with a high near 66. South wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 57. South wind around 10 mph.
Tuesday
Mostly cloudy, with a high near 72. South southwest wind around 10 mph becoming north northwest in the afternoon. Winds could gust as high as 20 mph.
Tuesday Night
Partly cloudy, with a low around 45. North wind around 10 mph.
Wednesday
Mostly sunny, with a high near 66. North wind around 10 mph, with gusts as high as 20 mph.
Wednesday Night
Mostly clear, with a low around 37.
Thursday
Sunny, with a high near 64.
Thursday Night
Mostly clear, with a low around 41.
Friday
Sunny, with a high near 71.
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:
11:28 am CST Jan 31, 2026
Forecast Valid:
11am CST Jan 31, 2026-6pm CST Feb 6, 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