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

81°F

27°C

Humidity 61%
Wind Speed S 20 G 25 mph
Barometer 29.95 in (1013.4 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 3 Apr 12:56 pm CDT
Extended Forecast for

San Marcos TX

  • This Afternoon

    This Afternoon: A 20 percent chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 87. South southeast wind around 15 mph, with gusts as high as 30 mph.

    High: 87 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: A 40 percent chance of showers and thunderstorms, mainly after 10pm. Mostly cloudy, with a low around 70. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.

    Low: 70 °F

    Chance
    T-storms

  • Saturday

    Saturday: Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1pm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 78 °F

    Showers

  • Saturday Night

    Saturday Night: Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 53. North wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.

    Low: 53 °F

    Showers
    Likely then
    Chance
    Showers

  • Sunday

    Sunday: A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 64. North northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 64 °F

    Chance
    Showers

  • Sunday Night

    Sunday Night: A 30 percent chance of showers, mainly before 1am. Cloudy, with a low around 53. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 53 °F

    Chance
    Showers

  • Monday

    Monday: Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.

    High: 70 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 50. East northeast wind around 5 mph becoming calm in the evening.

    Low: 50 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers after 1pm. Mostly cloudy, with a high near 68. North northeast wind around 5 mph becoming east in the afternoon.

    High: 68 °F

    Cloudy then
    Slight Chance
    Showers

Detailed Forecast

This Afternoon
A 20 percent chance of showers and thunderstorms after 4pm. Mostly cloudy, with a high near 87. South southeast wind around 15 mph, with gusts as high as 30 mph.
Tonight
A 40 percent chance of showers and thunderstorms, mainly after 10pm. Mostly cloudy, with a low around 70. South southeast wind 10 to 15 mph, with gusts as high as 30 mph.
Saturday
Showers and thunderstorms likely, then showers and possibly a thunderstorm after 1pm. High near 78. South southeast wind 5 to 15 mph becoming north in the afternoon. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Saturday Night
Showers likely and possibly a thunderstorm before 7pm, then a chance of showers and thunderstorms between 7pm and 1am, then a slight chance of showers after 1am. Mostly cloudy, with a low around 53. North wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 60%.
Sunday
A 30 percent chance of showers, mainly before 1pm. Mostly cloudy, with a high near 64. North northeast wind around 15 mph, with gusts as high as 25 mph.
Sunday Night
A 30 percent chance of showers, mainly before 1am. Cloudy, with a low around 53. North northeast wind 5 to 10 mph, with gusts as high as 20 mph.
Monday
Mostly cloudy, with a high near 70. Northeast wind 5 to 10 mph.
Monday Night
Mostly cloudy, with a low around 50. East northeast wind around 5 mph becoming calm in the evening.
Tuesday
A 20 percent chance of showers after 1pm. Mostly cloudy, with a high near 68. North northeast wind around 5 mph becoming east in the afternoon.
Tuesday Night
Mostly cloudy, with a low around 51.
Wednesday
Partly sunny, with a high near 78.
Wednesday Night
Mostly cloudy, with a low around 59.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81.
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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:
1:24 pm CDT Apr 3, 2026
Forecast Valid:
1pm CDT Apr 3, 2026-6pm CDT Apr 9, 2026
 
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