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

57°F

14°C

Humidity 34%
Wind Speed Vrbl 5 mph
Barometer 30.51 in (1033.0 mb)
Dewpoint 29°F (-2°C)
Visibility 10.00 mi
Last update 12 Jan 10:56 am CST
Extended Forecast for

3 Miles WSW San Marcos TX

  • Today

    Today: Partly sunny, with a high near 63. Calm wind becoming east northeast around 5 mph.

    High: 63 °F

    Partly Sunny

  • Tonight

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

    Low: 45 °F

    Mostly Cloudy
    then Chance
    Showers

  • Tuesday

    Tuesday: A 20 percent chance of showers before noon. Cloudy, then gradually becoming mostly sunny, with a high near 61. Southwest wind 5 to 10 mph.

    High: 61 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Tuesday Night

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

    Low: 42 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 70. West wind 5 to 10 mph becoming north 10 to 15 mph in the afternoon. Winds could gust as high as 30 mph.

    High: 70 °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.

    High: 68 °F

    Sunny

Detailed Forecast

Today
Partly sunny, with a high near 63. Calm wind becoming east northeast around 5 mph.
Tonight
A 30 percent chance of showers, mainly after 3am. Mostly cloudy, with a low around 45. Southeast wind around 5 mph becoming calm.
Tuesday
A 20 percent chance of showers before noon. Cloudy, then gradually becoming mostly sunny, with a high near 61. Southwest wind 5 to 10 mph.
Tuesday Night
Mostly clear, with a low around 42. Southwest wind around 5 mph.
Wednesday
Sunny, with a high near 70. 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.
Friday Night
Mostly clear, with a low around 41.
Saturday
Sunny, with a high near 64.
Saturday Night
Mostly clear, with a low around 38.
Sunday
Sunny, with a high near 64.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles WSW San Marcos TX
 29.86°N 97.97°W (Elev. 646 ft)
Last Update:
11:32 am CST Jan 12, 2026
Forecast Valid:
11am CST Jan 12, 2026-6pm CST Jan 18, 2026
 
Forecast Discussion
 
Get as KML Get as XML

Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation