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

Arctic Front Brings Winter Weather and Colder Temperatures to the Eastern U.S.

A series of cold fronts will bring heavy lake effect snow to the northern Great Lakes. The fronts will merge over the Ohio Valley and bring colder temperatures east of the Mississippi River later today into the end of the week. Additionally, wintry weather will develop over the Ohio Valley, Appalachians, and Northeast as rain switches over to snow tonight into Thursday morning. Read More >

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair and Breezy

66°F

19°C

Humidity 26%
Wind Speed N 22 G 30 mph
Barometer 30.15 in (1020.5 mb)
Dewpoint 30°F (-1°C)
Visibility 10.00 mi
Last update 14 Jan 4:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Clear, with a low around 37. North wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 37 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 65. Calm wind becoming south southwest around 5 mph in the afternoon.

    High: 65 °F

    Sunny

  • Thursday Night

    Thursday Night: Clear, with a low around 44. South wind 5 to 10 mph.

    Low: 44 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 72. Southwest wind around 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.

    High: 72 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 41. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 41 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 55. Northeast wind 5 to 10 mph.

    High: 55 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 32. Northeast wind around 5 mph becoming west northwest after midnight.

    Low: 32 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 62. West wind around 5 mph becoming south in the afternoon.

    High: 62 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 40. South wind around 5 mph.

    Low: 40 °F

    Mostly Clear

Detailed Forecast

Tonight
Clear, with a low around 37. North wind 5 to 15 mph, with gusts as high as 25 mph.
Thursday
Sunny, with a high near 65. Calm wind becoming south southwest around 5 mph in the afternoon.
Thursday Night
Clear, with a low around 44. South wind 5 to 10 mph.
Friday
Sunny, with a high near 72. Southwest wind around 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.
Friday Night
Mostly clear, with a low around 41. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Saturday
Mostly sunny, with a high near 55. Northeast wind 5 to 10 mph.
Saturday Night
Mostly clear, with a low around 32. Northeast wind around 5 mph becoming west northwest after midnight.
Sunday
Sunny, with a high near 62. West wind around 5 mph becoming south in the afternoon.
Sunday Night
Mostly clear, with a low around 40. South wind around 5 mph.
M.L.King Day
Partly sunny, with a high near 65.
Monday Night
Mostly cloudy, with a low around 43.
Tuesday
Mostly cloudy, with a high near 56.
Tuesday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 45.
Wednesday
A 20 percent chance of showers. Mostly cloudy, with a high near 62.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
4:44 pm CST Jan 14, 2026
Forecast Valid:
5pm CST Jan 14, 2026-6pm CST Jan 21, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation