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

Heavy Rainfall to Bring Flooding Threat to California; Heavy Snow in the Sierra

A strong atmospheric river will bring heavy rainfall to California through the holiday week. The heaviest rainfall is expected on Wednesday in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall is expected in the Sierra Nevada from the atmospheric river, raising concerns for major snow‐load impacts. Travel may be difficult to impossible over the passes. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

66°F

19°C

Humidity 100%
Wind Speed S 8 mph
Barometer 30.25 in (1023.7 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Last update 24 Dec 2:56 am CST
Extended Forecast for

4 Miles NNW San Marcos Municipal Airport TX

  • Overnight

    Overnight: Patchy dense fog. Otherwise, cloudy, with a low around 63. South wind around 5 mph.

    Low: 63 °F

    Patchy Dense
    Fog

  • Wednesday

    Wednesday: Areas of dense fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 79. South wind 5 to 10 mph.

    High: 79 °F

    Areas Dense
    Fog then
    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Increasing clouds, with a low around 61. South southwest wind around 5 mph.

    Low: 61 °F

    Increasing
    Clouds

  • Christmas Day

    Christmas Day: Cloudy through mid morning, then gradual clearing, with a high near 79. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 79 °F

    Gradual
    Clearing

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 61. South wind around 5 mph.

    Low: 61 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, with a high near 81. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 62. South wind 5 to 10 mph.

    Low: 62 °F

    Partly Cloudy

  • 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: Mostly cloudy, with a low around 63. South wind 5 to 10 mph.

    Low: 63 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Patchy dense fog. Otherwise, cloudy, with a low around 63. South wind around 5 mph.
Wednesday
Areas of dense fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 79. South wind 5 to 10 mph.
Wednesday Night
Increasing clouds, with a low around 61. South southwest wind around 5 mph.
Christmas Day
Cloudy through mid morning, then gradual clearing, with a high near 79. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
Partly cloudy, with a low around 61. South wind around 5 mph.
Friday
Partly sunny, with a high near 81. South southwest wind 5 to 10 mph, with gusts as high as 20 mph.
Friday Night
Partly cloudy, with a low around 62. 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
Mostly cloudy, with a low around 63. South wind 5 to 10 mph.
Sunday
Mostly cloudy, with a high near 76.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 41.
Monday
Mostly cloudy, with a high near 50.
Monday Night
Mostly cloudy, with a low around 33.
Tuesday
Mostly sunny, with a high near 56.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles NNW San Marcos Municipal Airport TX
 29.95°N 97.89°W (Elev. 646 ft)
Last Update:
2:32 am CST Dec 24, 2025
Forecast Valid:
3am CST Dec 24, 2025-6pm CST Dec 30, 2025
 
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