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

Rapid Warm-Up Forecast Across Much of the Lower 48 Today and Tuesday

Most of the U.S. starts the week calm and unseasonably warm. The Heartland will be warmest, with highs 25–30° above average. Only the Gulf Coast stays chilly. Rain today is limited to western Washington while lake effect snow continues east of Lake Ontario. Cooler air returns after Tuesday, bringing a wintry mix to the Midwest and Northeast by Wednesday. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

A Few Clouds

62°F

17°C

Humidity 26%
Wind Speed Calm
Barometer 30.36 in (1028.1 mb)
Dewpoint 27°F (-3°C)
Visibility 10.00 mi
Last update 12 Jan 4:56 pm CST
Extended Forecast for

4 Miles WNW San Marcos TX

  • Tonight

    Tonight: A 30 percent chance of showers, mainly after 3am. Mostly cloudy, with a low around 45. Calm wind becoming west around 5 mph after midnight.

    Low: 45 °F

    Mostly Cloudy
    then Chance
    Showers

  • Tuesday

    Tuesday: A 20 percent chance of showers before noon. Mostly cloudy, with a high near 61. West southwest wind around 5 mph.

    High: 61 °F

    Slight Chance
    Showers then
    Partly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 42. West wind around 5 mph.

    Low: 42 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 69. West wind 5 to 10 mph becoming north 10 to 15 mph in the afternoon. Winds could gust as high as 30 mph.

    High: 69 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Clear, with a low around 38. North wind 5 to 10 mph, with gusts as high as 25 mph.

    Low: 38 °F

    Clear

  • Thursday

    Thursday: Sunny, with a high near 62. North northwest wind around 5 mph becoming south southwest in the afternoon.

    High: 62 °F

    Sunny

  • Thursday Night

    Thursday Night: Clear, with a low around 40. South southeast wind around 5 mph becoming southwest after midnight.

    Low: 40 °F

    Clear

  • Friday

    Friday: Sunny, with a high near 68. Southwest wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.

    High: 68 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 40. North northeast wind around 5 mph.

    Low: 40 °F

    Mostly Clear

Detailed Forecast

Tonight
A 30 percent chance of showers, mainly after 3am. Mostly cloudy, with a low around 45. Calm wind becoming west around 5 mph after midnight.
Tuesday
A 20 percent chance of showers before noon. Mostly cloudy, with a high near 61. West southwest wind around 5 mph.
Tuesday Night
Mostly clear, with a low around 42. West wind around 5 mph.
Wednesday
Sunny, with a high near 69. West wind 5 to 10 mph becoming north 10 to 15 mph in the afternoon. Winds could gust as high as 30 mph.
Wednesday Night
Clear, with a low around 38. North wind 5 to 10 mph, with gusts as high as 25 mph.
Thursday
Sunny, with a high near 62. North northwest wind around 5 mph becoming south southwest in the afternoon.
Thursday Night
Clear, with a low around 40. South southeast wind around 5 mph becoming southwest after midnight.
Friday
Sunny, with a high near 68. Southwest wind 5 to 10 mph becoming north in the afternoon. Winds could gust as high as 20 mph.
Friday Night
Mostly clear, with a low around 40. North northeast wind around 5 mph.
Saturday
Sunny, with a high near 63.
Saturday Night
Mostly clear, with a low around 38.
Sunday
Sunny, with a high near 64.
Sunday Night
Mostly clear, with a low around 38.
M.L.King Day
Mostly sunny, with a high near 64.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles WNW San Marcos TX
 29.9°N 97.99°W (Elev. 850 ft)
Last Update:
5:42 pm CST Jan 12, 2026
Forecast Valid:
5pm CST Jan 12, 2026-6pm CST Jan 19, 2026
 
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Additional Resources

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Chance of Precipitation