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.

Overcast

70°F

21°C

Humidity 84%
Wind Speed NE 13 mph
Barometer 29.84 in (1009.9 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Last update 30 Apr 7:56 pm CDT
Extended Forecast for

5 Miles SW San Marcos TX

Flood Watch April 30, 09:00pm until May 1, 09:00pm
Click here for hazard details and duration
Flood Watch

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 61. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 61 °F

    Chance
    T-storms then
    Showers

  • Friday

    Friday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 63. Northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.

    High: 63 °F

    Heavy Rain

  • Friday Night

    Friday Night: Showers likely, mainly before 7pm. Mostly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 51 °F

    Showers
    Likely then
    Slight Chance
    Showers

  • Saturday

    Saturday: Sunny, with a high near 72. North wind 10 to 15 mph, with gusts as high as 20 mph.

    High: 72 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 50. Northeast wind 5 to 10 mph becoming light and variable in the evening.

    Low: 50 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 77. Calm wind becoming south southeast around 5 mph in the afternoon.

    High: 77 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 56. South southeast wind around 5 mph.

    Low: 56 °F

    Mostly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 83. South wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 83 °F

    Partly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 66. South wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 66 °F

    Mostly Cloudy

Detailed Forecast

Tonight
A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 1am. Low around 61. Northeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Friday
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 63. Northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Friday Night
Showers likely, mainly before 7pm. Mostly cloudy, with a low around 51. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
Sunny, with a high near 72. North wind 10 to 15 mph, with gusts as high as 20 mph.
Saturday Night
Mostly clear, with a low around 50. Northeast wind 5 to 10 mph becoming light and variable in the evening.
Sunday
Mostly sunny, with a high near 77. Calm wind becoming south southeast around 5 mph in the afternoon.
Sunday Night
Mostly cloudy, with a low around 56. South southeast wind around 5 mph.
Monday
Partly sunny, with a high near 83. South wind 5 to 15 mph, with gusts as high as 25 mph.
Monday Night
Mostly cloudy, with a low around 66. South wind 10 to 15 mph, with gusts as high as 20 mph.
Tuesday
Mostly cloudy, with a high near 90.
Tuesday Night
Mostly cloudy, with a low around 70.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 88.
Wednesday Night
Mostly cloudy, with a low around 63.
Thursday
A 20 percent chance of showers. Partly sunny, with a high near 79.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
5 Miles SW San Marcos TX
 29.83°N 97.99°W (Elev. 676 ft)
Last Update:
6:48 pm CDT Apr 30, 2026
Forecast Valid:
8pm CDT Apr 30, 2026-6pm CDT May 7, 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