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

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

73°F

23°C

Humidity 71%
Wind Speed S 14 mph
Barometer 30.19 in (1021.8 mb)
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 25 Dec 11:56 am CST
Extended Forecast for

San Marcos TX

  • Christmas Day

    Christmas Day: Partly sunny, with a high near 79. South wind 5 to 10 mph.

    High: 79 °F

    Partly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 64. South southwest wind around 5 mph.

    Low: 64 °F

    Increasing
    Clouds

  • Friday

    Friday: Cloudy through mid morning, then gradual clearing, with a high near 81. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Gradual
    Clearing

  • Friday Night

    Friday Night: Increasing clouds, with a low around 66. South wind 5 to 10 mph.

    Low: 66 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Partly sunny, with a high near 81. South wind around 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 65. South wind around 10 mph.

    Low: 65 °F

    Partly Cloudy

  • Sunday

    Sunday: Mostly cloudy, with a high near 80. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 80 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 42. Southwest wind 5 to 10 mph becoming north 15 to 20 mph in the evening. Winds could gust as high as 30 mph. Chance of precipitation is 30%.

    Low: 42 °F

    Chance
    Showers

  • Monday

    Monday: Cloudy, with a high near 49. North wind 15 to 20 mph, with gusts as high as 35 mph.

    High: 49 °F

    Cloudy

Detailed Forecast

Christmas Day
Partly sunny, with a high near 79. South wind 5 to 10 mph.
Tonight
Increasing clouds, with a low around 64. South southwest wind around 5 mph.
Friday
Cloudy through mid morning, then gradual clearing, with a high near 81. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
Increasing clouds, with a low around 66. South wind 5 to 10 mph.
Saturday
Partly sunny, with a high near 81. South wind around 10 mph, with gusts as high as 20 mph.
Saturday Night
Partly cloudy, with a low around 65. South wind around 10 mph.
Sunday
Mostly cloudy, with a high near 80. South wind 5 to 10 mph, with gusts as high as 20 mph.
Sunday Night
A chance of showers, with thunderstorms also possible after midnight. Mostly cloudy, with a low around 42. Southwest wind 5 to 10 mph becoming north 15 to 20 mph in the evening. Winds could gust as high as 30 mph. Chance of precipitation is 30%.
Monday
Cloudy, with a high near 49. North wind 15 to 20 mph, with gusts as high as 35 mph.
Monday Night
Mostly cloudy, with a low around 35.
Tuesday
Mostly cloudy, with a high near 53.
Tuesday Night
Mostly cloudy, with a low around 35.
Wednesday
Mostly sunny, with a high near 61.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
11:44 am CST Dec 25, 2025
Forecast Valid:
12pm CST Dec 25, 2025-6pm CST Dec 31, 2025
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation