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

Showers and Thunderstorms in the Southwest and Ohio Valley; Mountain Snow in the Northeast

Showers and thunderstorms, along with high-elevation snow, will begin to develop over parts of the Southwest late tonight and is expected to continue through Wednesday morning. Mountain snow over parts the Northeast will continue through Tuesday. A few strong to severe storms and heavy rainfall are possible across portions of the Lower Ohio Valley Tuesday. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

75°F

24°C

Humidity 84%
Wind Speed S 12 mph
Barometer 29.94 in (1013.1 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Last update 17 Nov 10:56 pm CST
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Mostly cloudy, with a low around 70. South wind around 10 mph.

    Low: 70 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 85. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 85 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Patchy fog after 5am. Otherwise, increasing clouds, with a low around 69. South wind around 5 mph.

    Low: 69 °F

    Partly Cloudy
    then Patchy
    Fog

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after noon. Areas of fog before 8am. Otherwise, mostly cloudy, with a high near 85. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 40%.

    High: 85 °F

    Chance
    Showers and
    Areas Fog

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms. Patchy fog after 5am. Otherwise, cloudy, with a low around 69. South southeast wind around 10 mph.

    Low: 69 °F

    Chance
    T-storms then
    Chance
    Showers and
    Patchy Fog

  • Thursday

    Thursday: Showers likely and possibly a thunderstorm. Areas of fog before 8am. Otherwise, mostly cloudy, with a high near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%.

    High: 77 °F

    Showers
    Likely and
    Areas Fog

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 63. South southeast wind 5 to 10 mph becoming west after midnight. Chance of precipitation is 70%.

    Low: 63 °F

    Showers
    Likely

  • Friday

    Friday: A 30 percent chance of showers before noon. Mostly sunny, with a high near 80. Northwest wind around 5 mph.

    High: 80 °F

    Chance
    Showers then
    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 56. North wind around 5 mph.

    Low: 56 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly cloudy, with a low around 70. South wind around 10 mph.
Tuesday
Partly sunny, with a high near 85. South wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday Night
Patchy fog after 5am. Otherwise, increasing clouds, with a low around 69. South wind around 5 mph.
Wednesday
A chance of showers, with thunderstorms also possible after noon. Areas of fog before 8am. Otherwise, mostly cloudy, with a high near 85. South southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 40%.
Wednesday Night
A 40 percent chance of showers and thunderstorms. Patchy fog after 5am. Otherwise, cloudy, with a low around 69. South southeast wind around 10 mph.
Thursday
Showers likely and possibly a thunderstorm. Areas of fog before 8am. Otherwise, mostly cloudy, with a high near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%.
Thursday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 63. South southeast wind 5 to 10 mph becoming west after midnight. Chance of precipitation is 70%.
Friday
A 30 percent chance of showers before noon. Mostly sunny, with a high near 80. Northwest wind around 5 mph.
Friday Night
Mostly clear, with a low around 56. North wind around 5 mph.
Saturday
A 20 percent chance of showers. Mostly sunny, with a high near 74.
Saturday Night
A 30 percent chance of showers. Partly cloudy, with a low around 53.
Sunday
A 30 percent chance of showers. Partly sunny, with a high near 71.
Sunday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 54.
Monday
A 30 percent chance of showers. Mostly sunny, with a high near 73.
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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:
11:02 pm CST Nov 17, 2025
Forecast Valid:
11pm CST Nov 17, 2025-6pm CST Nov 24, 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