Areas of Excessive Rainfall and Severe Thunderstorms; Fire Weather Concerns in the Northern Plains and Four Corners Region

Widespread showers and thunderstorms may bring areas of flash flooding across much of the Southern Plains into the Gulf Coast region and the upper Ohio River Valley into the Mid-Atlantic. A large Pacific storm will bring widespread rain, gusty winds, and mountain snow to California and the Great Basin. Fire weather concerns expected in the Northern Plains and the Four Corners region. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

78°F

26°C

Humidity 79%
Wind Speed SE 7 mph
Barometer 29.84 in (1009.7 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 26 May 9:56 pm CDT
Extended Forecast for

San Marcos TX

Flood Watch May 26, 10:14pm until May 27, 08:00am
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch May 26, 10:14pm until May 27, 08:00am

    NOW until 8:00am Wed

    Flood Watch

  • Tonight

    Low: 70 °F

    Showers
    Likely then
    T-storms

  • Wednesday

    Wednesday: A 50 percent chance of showers and thunderstorms.  Partly sunny, with a high near 83. East wind around 5 mph.  New rainfall amounts between a quarter and half of an inch possible.

    High: 83 °F

    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms before 1am.  Mostly cloudy, with a low around 70. East wind around 5 mph becoming calm  in the evening.

    Low: 70 °F

    Slight Chance
    T-storms

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms after 1pm.  Mostly cloudy, then gradually becoming sunny, with a high near 86. Calm wind becoming east around 5 mph in the afternoon.

    High: 86 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 72. East wind around 5 mph becoming calm  in the evening.

    Low: 72 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 89. Calm wind becoming south around 5 mph in the afternoon.

    High: 89 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 73. South wind around 5 mph.

    Low: 73 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly cloudy, with a high near 89. South southwest wind around 5 mph.

    High: 89 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Showers and possibly a thunderstorm. Low around 70. South southeast wind around 5 mph becoming northeast after midnight. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 83. East wind around 5 mph. New rainfall amounts between a quarter and half of an inch possible.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 70. East wind around 5 mph becoming calm in the evening.
Thursday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, then gradually becoming sunny, with a high near 86. Calm wind becoming east around 5 mph in the afternoon.
Thursday Night
Partly cloudy, with a low around 72. East wind around 5 mph becoming calm in the evening.
Friday
Mostly sunny, with a high near 89. Calm wind becoming south around 5 mph in the afternoon.
Friday Night
Partly cloudy, with a low around 73. South wind around 5 mph.
Saturday
Mostly cloudy, with a high near 89. South southwest wind around 5 mph.
Saturday Night
A 40 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 73. South wind around 5 mph.
Sunday
A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 89.
Sunday Night
A 40 percent chance of showers and thunderstorms. Partly cloudy, with a low around 72.
Monday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 88.
Monday Night
A 30 percent chance of showers and thunderstorms. Partly cloudy, with a low around 72.
Tuesday
A 30 percent chance of showers and thunderstorms. Mostly sunny, with a high near 86.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
9:46 pm CDT May 26, 2026
10pm CDT May 26, 2026-6pm CDT Jun 2, 2026
 
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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