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

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

84°F

29°C

Humidity 74%
Wind Speed SE 15 G 20 mph
Barometer 30.04 in (1016.6 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index92°F (33°C)
Last update 12 Oct 10:56 am CDT
Extended Forecast for

4 Miles S San Marcos TX

  • Columbus Day

    Columbus Day: A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Heat index values as high as 100. South wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

    High: 91 °F

    Chance
    Showers

  • Tonight

    Tonight: Increasing clouds, with a low around 75. Southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 75 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: Partly sunny, with a high near 93. Heat index values as high as 103. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 93 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 75. South southeast wind around 10 mph, with gusts as high as 25 mph.

    Low: 75 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 91 °F

    Partly Sunny
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 71. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 71 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 89. Southeast wind around 5 mph.

    High: 89 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 67. Light and variable wind becoming north 10 to 15 mph after midnight.

    Low: 67 °F

    Mostly Clear

  • Friday

    Friday: Mostly sunny, with a high near 80. Breezy, with a north northeast wind 20 to 25 mph, with gusts as high as 35 mph.

    High: 80 °F

    Mostly Sunny
    and Breezy

Detailed Forecast

Columbus Day
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Heat index values as high as 100. South wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.
Tonight
Increasing clouds, with a low around 75. Southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday
Partly sunny, with a high near 93. Heat index values as high as 103. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Partly cloudy, with a low around 75. South southeast wind around 10 mph, with gusts as high as 25 mph.
Wednesday
A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. South southeast wind 10 to 15 mph, with gusts as high as 25 mph.
Wednesday Night
Partly cloudy, with a low around 71. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Thursday
Mostly sunny, with a high near 89. Southeast wind around 5 mph.
Thursday Night
Mostly clear, with a low around 67. Light and variable wind becoming north 10 to 15 mph after midnight.
Friday
Mostly sunny, with a high near 80. Breezy, with a north northeast wind 20 to 25 mph, with gusts as high as 35 mph.
Friday Night
Mostly cloudy, with a low around 59.
Saturday
Mostly sunny, with a high near 73.
Saturday Night
Partly cloudy, with a low around 54.
Sunday
Mostly sunny, with a high near 77.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles S San Marcos TX
 29.83°N 97.94°W (Elev. 610 ft)
Last Update:
6:42 am CDT Oct 12, 2026
Forecast Valid:
11am CDT Oct 12, 2026-6pm CDT Oct 18, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation