Cold Temperatures for the Eastern U.S.; Lake Effect Snow in the Great Lakes; Heavy Rain in the Pacific Northwest

Cold temperatures will continue across much of the eastern U.S. into today. Heavy lake effect snow continues into today east of Lakes Erie and Ontario. Two Pacific cold fronts will cross the Pacific Northwest early this week followed by another atmospheric river. Heavy rain and gusty winds are expected through midweek, with the potential for renewed urban and river flooding. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

55°F

13°C

Humidity 26%
Wind Speed SE 7 mph
Barometer 30.30 in (1026.1 mb)
Dewpoint 21°F (-6°C)
Visibility 10.00 mi
Wind Chill53°F (12°C)
Last update 15 Dec 4:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Mostly cloudy, with a low around 41. South wind around 5 mph becoming calm  after midnight.

    Low: 41 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Cloudy, with a high near 62. Calm wind becoming south around 5 mph in the morning.

    High: 62 °F

    Cloudy

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers.  Patchy fog after 10pm.  Otherwise, cloudy, with a low around 55. South wind around 5 mph becoming calm  in the evening.

    Low: 55 °F

    Chance
    Showers and
    Patchy Fog

  • Wednesday

    Wednesday: A chance of showers and thunderstorms.  Patchy fog before 11am.  Otherwise, cloudy, with a high near 67. Calm wind becoming south southeast around 5 mph in the afternoon.  Chance of precipitation is 30%.

    High: 67 °F

    Chance
    Showers and
    Patchy Fog

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 61. South wind around 5 mph.

    Low: 61 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 79. Southwest wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.

    High: 79 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 45. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 45 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 68. North northeast wind around 5 mph becoming south southeast in the afternoon.

    High: 68 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 51. South southwest wind 5 to 10 mph.

    Low: 51 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 41. South wind around 5 mph becoming calm after midnight.
Tuesday
Cloudy, with a high near 62. Calm wind becoming south around 5 mph in the morning.
Tuesday Night
A 30 percent chance of showers. Patchy fog after 10pm. Otherwise, cloudy, with a low around 55. South wind around 5 mph becoming calm in the evening.
Wednesday
A chance of showers and thunderstorms. Patchy fog before 11am. Otherwise, cloudy, with a high near 67. Calm wind becoming south southeast around 5 mph in the afternoon. Chance of precipitation is 30%.
Wednesday Night
Mostly cloudy, with a low around 61. South wind around 5 mph.
Thursday
Mostly sunny, with a high near 79. Southwest wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.
Thursday Night
Mostly clear, with a low around 45. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Friday
Sunny, with a high near 68. North northeast wind around 5 mph becoming south southeast in the afternoon.
Friday Night
Mostly clear, with a low around 51. South southwest wind 5 to 10 mph.
Saturday
Mostly sunny, with a high near 77.
Saturday Night
Mostly clear, with a low around 58.
Sunday
Mostly sunny, with a high near 79.
Sunday Night
Partly cloudy, with a low around 58.
Monday
Partly sunny, with a high near 78.
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
5:46 pm CST Dec 15, 2025
5pm CST Dec 15, 2025-6pm CST Dec 22, 2025
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

National Digital Forecast Database