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.

Mostly Cloudy

79°F

26°C

Humidity 97%
Wind Speed SE 10 mph
Barometer 30.07 in (1017.2 mb)
Dewpoint 78°F (26°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 22 Jun 12:56 am CDT
Extended Forecast for

San Marcos TX

  • Overnight

    Overnight: Mostly cloudy, with a low around 75. South southeast wind 5 to 10 mph.

    Low: 75 °F

    Mostly Cloudy

  • Sunday

    Sunday: Mostly sunny, with a high near 93. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 93 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 74. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 74 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 94. Heat index values as high as 100. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 94 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 72. Southeast wind 5 to 10 mph becoming light south southeast after midnight. Winds could gust as high as 20 mph.

    Low: 72 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 93. Light east southeast wind becoming southeast 5 to 10 mph in the morning.

    High: 93 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 72. Southeast wind 5 to 10 mph becoming light south southeast after midnight.

    Low: 72 °F

    Mostly Clear

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Light east southeast wind becoming southeast 5 to 10 mph in the morning.

    High: 92 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 72. Southeast wind 5 to 10 mph becoming light south after midnight.

    Low: 72 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 75. South southeast wind 5 to 10 mph.
Sunday
Mostly sunny, with a high near 93. South southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Sunday Night
Partly cloudy, with a low around 74. Southeast wind 5 to 15 mph, with gusts as high as 25 mph.
Monday
Mostly sunny, with a high near 94. Heat index values as high as 100. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday Night
Mostly clear, with a low around 72. Southeast wind 5 to 10 mph becoming light south southeast after midnight. Winds could gust as high as 20 mph.
Tuesday
Mostly sunny, with a high near 93. Light east southeast wind becoming southeast 5 to 10 mph in the morning.
Tuesday Night
Mostly clear, with a low around 72. Southeast wind 5 to 10 mph becoming light south southeast after midnight.
Wednesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 92. Light east southeast wind becoming southeast 5 to 10 mph in the morning.
Wednesday Night
Partly cloudy, with a low around 72. Southeast wind 5 to 10 mph becoming light south after midnight.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly sunny, with a high near 93.
Thursday Night
Partly cloudy, with a low around 73.
Friday
Mostly sunny, with a high near 93.
Friday Night
Partly cloudy, with a low around 73.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93.
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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:
1:38 am CDT Jun 22, 2025
Forecast Valid:
1am CDT Jun 22, 2025-6pm CDT Jun 28, 2025
 
Forecast Discussion
 
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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