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.

Partly Cloudy

77°F

25°C

Humidity 94%
Wind Speed S 5 mph
Barometer 30.07 in (1017.6 mb)
Dewpoint 75°F (24°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 12 Jul 1:56 am CDT
Extended Forecast for

2 Miles WSW San Marcos TX

  • Overnight

    Overnight: Mostly cloudy, with a low around 75. South wind around 5 mph.

    Low: 75 °F

    Mostly Cloudy

  • Sunday

    Sunday: A 20 percent chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 92. Heat index values as high as 101. Calm wind becoming south southeast around 5 mph in the morning.

    High: 92 °F

    Partly Sunny
    then Slight
    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 20 percent chance of showers and thunderstorms before 7pm. Increasing clouds, with a low around 76. Southeast wind 5 to 10 mph becoming light south after midnight.

    Low: 76 °F

    Slight Chance
    T-storms then
    Mostly Cloudy

  • 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 100. Calm wind becoming south around 5 mph in the afternoon.

    High: 91 °F

    Partly Sunny
    then Chance
    T-storms

  • Monday Night

    Monday Night: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 75. Southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.

    Low: 75 °F

    Chance
    T-storms then
    Showers
    Likely

  • Tuesday

    Tuesday: Showers and possibly a thunderstorm. High near 86. Calm wind becoming south southeast around 5 mph in the afternoon. Chance of precipitation is 80%.

    High: 86 °F

    Showers

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 72. East southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 50%.

    Low: 72 °F

    Chance
    T-storms then
    Chance
    Showers

  • Wednesday

    Wednesday: Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 87. Calm wind becoming southeast around 5 mph in the afternoon. Chance of precipitation is 60%.

    High: 87 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 72. East southeast wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Slight Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Overnight
Mostly cloudy, with a low around 75. South wind around 5 mph.
Sunday
A 20 percent chance of showers and thunderstorms after 4pm. Mostly sunny, with a high near 92. Heat index values as high as 101. Calm wind becoming south southeast around 5 mph in the morning.
Sunday Night
A 20 percent chance of showers and thunderstorms before 7pm. Increasing clouds, with a low around 76. Southeast wind 5 to 10 mph becoming light south after midnight.
Monday
A 40 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 91. Heat index values as high as 100. Calm wind becoming south around 5 mph in the afternoon.
Monday Night
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1am. Mostly cloudy, with a low around 75. Southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 60%.
Tuesday
Showers and possibly a thunderstorm. High near 86. Calm wind becoming south southeast around 5 mph in the afternoon. Chance of precipitation is 80%.
Tuesday Night
A chance of showers and thunderstorms before 10pm, then a chance of showers between 10pm and 1am, then a chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 72. East southeast wind around 5 mph becoming calm in the evening. Chance of precipitation is 50%.
Wednesday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 87. Calm wind becoming southeast around 5 mph in the afternoon. Chance of precipitation is 60%.
Wednesday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 72. East southeast wind around 5 mph becoming calm in the evening.
Thursday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 90.
Thursday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 74.
Friday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 91.
Friday Night
Partly cloudy, with a low around 74.
Saturday
Mostly sunny, with a high near 93.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles WSW San Marcos TX
 29.86°N 97.97°W (Elev. 646 ft)
Last Update:
2:11 am CDT Jul 12, 2026
Forecast Valid:
2am CDT Jul 12, 2026-6pm CDT Jul 18, 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