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

Prolonged Atmospheric River Will Impact the Northwest Early this Week

A weather system in the Pacific Northwest will produce rain throughout the day, before a potent atmospheric river produces a prolonged round of heavy rainfall, widespread urban and river flooding, and high elevation snow to the region Monday through Wednesday. Showers and thunderstorms may produce isolated damaging winds, a brief tornado, and locally heavy rainfall across parts of Florida today. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

46°F

8°C

Humidity 71%
Wind Speed N 12 mph
Barometer 30.28 in (1025.1 mb)
Dewpoint 37°F (3°C)
Visibility 10.00 mi
Wind Chill40°F (4°C)
Last update 8 Dec 12:56 am CST
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Clear, with a low around 40. North wind around 10 mph, with gusts as high as 20 mph.

    Low: 40 °F

    Clear

  • Monday

    Monday: Sunny, with a high near 62. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 62 °F

    Sunny

  • Monday Night

    Monday Night: Clear, with a low around 37. East northeast wind around 5 mph becoming calm.

    Low: 37 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 67. Light west southwest wind becoming south southwest 5 to 10 mph in the afternoon. Winds could gust as high as 20 mph.

    High: 67 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Clear, with a low around 46. Southwest wind around 5 mph.

    Low: 46 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 75. Southwest wind 5 to 10 mph becoming southeast in the afternoon.

    High: 75 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 47. East wind around 5 mph becoming north after midnight.

    Low: 47 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 75. North wind around 5 mph becoming south in the afternoon.

    High: 75 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 52. South wind around 5 mph becoming northwest after midnight.

    Low: 52 °F

    Mostly Clear

Detailed Forecast

Overnight
Clear, with a low around 40. North wind around 10 mph, with gusts as high as 20 mph.
Monday
Sunny, with a high near 62. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
Clear, with a low around 37. East northeast wind around 5 mph becoming calm.
Tuesday
Sunny, with a high near 67. Light west southwest wind becoming south southwest 5 to 10 mph in the afternoon. Winds could gust as high as 20 mph.
Tuesday Night
Clear, with a low around 46. Southwest wind around 5 mph.
Wednesday
Sunny, with a high near 75. Southwest wind 5 to 10 mph becoming southeast in the afternoon.
Wednesday Night
Mostly clear, with a low around 47. East wind around 5 mph becoming north after midnight.
Thursday
Sunny, with a high near 75. North wind around 5 mph becoming south in the afternoon.
Thursday Night
Mostly clear, with a low around 52. South wind around 5 mph becoming northwest after midnight.
Friday
Mostly sunny, with a high near 71.
Friday Night
Partly cloudy, with a low around 47.
Saturday
Partly sunny, with a high near 62.
Saturday Night
Mostly cloudy, with a low around 49.
Sunday
Mostly cloudy, with a high near 61.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
12:50 am CST Dec 8, 2025
Forecast Valid:
1am CST Dec 8, 2025-6pm CST Dec 14, 2025
 
Forecast Discussion
 
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Additional Resources

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National Digital Forecast Database

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High Temperature

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Chance of Precipitation