Heavy Great Lakes Snow through Friday; Extreme Cold and Potential for Major Winter Storm Late Week into this Weekend

Multiple clipper systems will bring cold temperatures and enhance lake-effect snow downwind of the Great Lakes. An arctic blast will bring frigid temperatures accompanied with gusty winds that may lead to dangerous wind chills beginning in the Northern Plains Thursday before expanding to the South and East. An expansive winter storm will start Friday in the Southern Rockies/Plains and Mid-South. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

58°F

14°C

Humidity 78%
Wind Speed S 7 mph
Barometer 30.16 in (1021.0 mb)
Dewpoint 51°F (11°C)
Visibility 10.00 mi
Last update 21 Jan 1:56 am CST
Extended Forecast for

4 Miles SSW San Marcos TX

  • Overnight

    Overnight: A 20 percent chance of showers.  Patchy fog before 5am.  Otherwise, cloudy, with a low around 52. South southeast wind around 5 mph.

    Low: 52 °F

    Slight Chance
    Showers and
    Patchy Fog

  • Wednesday

    Wednesday: A slight chance of showers between 9am and 3pm.  Cloudy, then gradually becoming mostly sunny, with a high near 69. Southwest wind around 5 mph.  Chance of precipitation is 20%.

    High: 69 °F

    Slight Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 52. North wind around 5 mph.

    Low: 52 °F

    Partly Cloudy

  • Thursday

    Thursday: Partly sunny, with a high near 71. North wind around 5 mph becoming southeast in the afternoon.

    High: 71 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 57. South southeast wind around 5 mph.

    Low: 57 °F

    Mostly Cloudy

  • Friday

    Friday: A 50 percent chance of showers.  Cloudy, with a high near 69. South southeast wind 5 to 10 mph becoming north northeast in the afternoon. Winds could gust as high as 20 mph.

    High: 69 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Showers.  Low around 31. North northeast wind around 15 mph, with gusts as high as 25 mph.  Chance of precipitation is 90%.

    Low: 31 °F

    Showers

  • Saturday

    Saturday: Rain showers, possibly mixed with sleet before noon, then rain showers and freezing rain likely, possibly mixed with sleet.  High near 35. North wind 15 to 20 mph, with gusts as high as 30 mph.  Chance of precipitation is 80%.

    High: 35 °F

    Wintry Mix

  • Saturday Night

    Saturday Night: Freezing rain likely, mainly before midnight.  Mostly cloudy, with a low around 18. North wind around 15 mph, with gusts as high as 30 mph.  Chance of precipitation is 60%.

    Low: 18 °F

    Freezing Rain
    Likely

Detailed Forecast

Overnight
A 20 percent chance of showers. Patchy fog before 5am. Otherwise, cloudy, with a low around 52. South southeast wind around 5 mph.
Wednesday
A slight chance of showers between 9am and 3pm. Cloudy, then gradually becoming mostly sunny, with a high near 69. Southwest wind around 5 mph. Chance of precipitation is 20%.
Wednesday Night
Partly cloudy, with a low around 52. North wind around 5 mph.
Thursday
Partly sunny, with a high near 71. North wind around 5 mph becoming southeast in the afternoon.
Thursday Night
Mostly cloudy, with a low around 57. South southeast wind around 5 mph.
Friday
A 50 percent chance of showers. Cloudy, with a high near 69. South southeast wind 5 to 10 mph becoming north northeast in the afternoon. Winds could gust as high as 20 mph.
Friday Night
Showers. Low around 31. North northeast wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%.
Saturday
Rain showers, possibly mixed with sleet before noon, then rain showers and freezing rain likely, possibly mixed with sleet. High near 35. North wind 15 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 80%.
Saturday Night
Freezing rain likely, mainly before midnight. Mostly cloudy, with a low around 18. North wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.
Sunday
A slight chance of freezing rain before noon. Partly sunny, with a high near 32. Chance of precipitation is 20%.
Sunday Night
Partly cloudy, with a low around 16.
Monday
Sunny, with a high near 41.
Monday Night
Mostly clear, with a low around 19.
Tuesday
Sunny, with a high near 48.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSW San Marcos TX
 29.83°N 97.94°W (Elev. 610 ft)
12:44 am CST Jan 21, 2026
2am CST Jan 21, 2026-6pm CST Jan 27, 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