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

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Fair

83°F

28°C

Humidity 74%
Wind Speed N 5 mph
Barometer 30.00 in (1015.2 mb)
Dewpoint 74°F (23°C)
Visibility 10.00 mi
Heat Index90°F (32°C)
Last update 13 Jul 3:56 pm CDT
Extended Forecast for

San Marcos TX

Flood Watch July 13, 04:22pm until July 13, 07:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch July 13, 04:22pm until July 13, 07:00pm

    NOW until 7:00pm Sun

    Flood Watch

  • This Afternoon

    High: 88 °F

    T-storms
    Likely

  • Tonight

    Tonight: Showers and thunderstorms likely, mainly before 10pm. Mostly cloudy, with a low around 74. Southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 74 °F

    T-storms
    Likely then
    Slight Chance
    T-storms

  • Monday

    Monday: A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Heat index values as high as 101. Calm wind becoming south southwest around 5 mph in the morning.

    High: 91 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 74. South wind around 5 mph.

    Low: 74 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Partly sunny, with a high near 92. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    High: 92 °F

    Mostly Cloudy
    then Slight
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 74. South southeast wind 5 to 10 mph.

    Low: 74 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 94 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 73. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 73 °F

    Mostly Clear

Detailed Forecast

This Afternoon
Showers and thunderstorms likely. Mostly cloudy, with a high near 88. East southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
Showers and thunderstorms likely, mainly before 10pm. Mostly cloudy, with a low around 74. Southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday
A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Heat index values as high as 101. Calm wind becoming south southwest around 5 mph in the morning.
Monday Night
Mostly cloudy, with a low around 74. South wind around 5 mph.
Tuesday
A slight chance of showers between 1pm and 4pm, then a slight chance of showers and thunderstorms after 4pm. Partly sunny, with a high near 92. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Tuesday Night
Mostly cloudy, with a low around 74. South southeast wind 5 to 10 mph.
Wednesday
Mostly sunny, with a high near 94. South wind 5 to 10 mph, with gusts as high as 20 mph.
Wednesday Night
Mostly clear, with a low around 73. South southeast wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday
Mostly sunny, with a high near 94. South wind 5 to 10 mph.
Thursday Night
Partly cloudy, with a low around 72.
Friday
Mostly sunny, with a high near 93.
Friday Night
Partly cloudy, with a low around 74.
Saturday
Mostly sunny, with a high near 94.
Saturday Night
Partly cloudy, with a low around 75.
Sunday
Mostly sunny, with a high near 95.
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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:
3:32 pm CDT Jul 13, 2025
Forecast Valid:
4pm CDT Jul 13, 2025-6pm CDT Jul 20, 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