Powerful Winter Storm from the Upper Midwest into the Northeast; Severe Thunderstorms in the Midwest and Ohio Valley

A rapidly-intensifying storm is expected to bring heavy snow, blizzard conditions, and icing from the Upper Midwest through the Great Lakes and Northeast. Scattered severe thunderstorms may produce severe/damaging wind gusts and a couple of tornadoes across parts of the Midwest and lower Ohio Valley through the evening. Arctic air will expand across the central and southern U.S.. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Mostly Cloudy

78°F

26°C

Humidity 64%
Wind Speed NW 3 mph
Barometer 29.96 in (1013.9 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 28 Dec 3:56 pm CST
Extended Forecast for

San Marcos TX

Wind Advisory December 28, 06:00pm until December 29, 12:00pm
Click here for hazard details and duration
Wind Advisory
  • Tonight

    Tonight: A 20 percent chance of showers before midnight.  Mostly cloudy, with a low around 43. Light and variable wind becoming north 15 to 20 mph in the evening. Winds could gust as high as 40 mph.

    Low: 43 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Monday

    Monday: A slight chance of sprinkles after 9am.  Mostly cloudy, with a high near 49. North northeast wind 15 to 20 mph, with gusts as high as 40 mph.

    High: 49 °F

    Slight Chance
    Sprinkles

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 37. North wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 37 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 57. North wind 5 to 10 mph.

    High: 57 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 33. Calm wind.

    Low: 33 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 64. Calm wind becoming southwest around 5 mph in the morning.

    High: 64 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 41. South southwest wind around 5 mph.

    Low: 41 °F

    Partly Cloudy

  • New Year's Day

    New Year's Day: Partly sunny, with a high near 71. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 71 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 53. South southwest wind around 5 mph.

    Low: 53 °F

    Partly Cloudy

Detailed Forecast

Tonight
A 20 percent chance of showers before midnight. Mostly cloudy, with a low around 43. Light and variable wind becoming north 15 to 20 mph in the evening. Winds could gust as high as 40 mph.
Monday
A slight chance of sprinkles after 9am. Mostly cloudy, with a high near 49. North northeast wind 15 to 20 mph, with gusts as high as 40 mph.
Monday Night
Mostly cloudy, with a low around 37. North wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday
Mostly sunny, with a high near 57. North wind 5 to 10 mph.
Tuesday Night
Mostly clear, with a low around 33. Calm wind.
Wednesday
Mostly sunny, with a high near 64. Calm wind becoming southwest around 5 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 41. South southwest wind around 5 mph.
New Year's Day
Partly sunny, with a high near 71. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Partly cloudy, with a low around 53. South southwest wind around 5 mph.
Friday
Sunny, with a high near 81.
Friday Night
Mostly clear, with a low around 51.
Saturday
Sunny, with a high near 75.
Saturday Night
Mostly clear, with a low around 48.
Sunday
Mostly sunny, with a high near 73.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.9°N 97.91°W (Elev. 640 ft)
3:46 pm CST Dec 28, 2025
4pm CST Dec 28, 2025-6pm CST Jan 4, 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