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.

Fair with Haze

81°F

27°C

Humidity 79%
Wind Speed SE 10 mph
Barometer 29.84 in (1009.4 mb)
Dewpoint 74°F (23°C)
Visibility 2.50 mi
Heat Index86°F (30°C)
Last update 27 Apr 8:56 pm CDT
Extended Forecast for

4 Miles NNW San Marcos Municipal Airport TX

  • Tonight

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

    Low: 74 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Cloudy, then gradually becoming mostly sunny, with a high near 92. Heat index values as high as 100. South wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 92 °F

    Decreasing
    Clouds

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 71. South wind 5 to 10 mph, with gusts as high as 20 mph.

    Low: 71 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 89. South wind 5 to 10 mph becoming northeast in the afternoon.

    High: 89 °F

    Mostly Cloudy
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 66. Northeast wind 5 to 10 mph.

    Low: 66 °F

    Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms. Cloudy, with a high near 82. East wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 82 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 65. East northeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 65 °F

    Chance
    T-storms

  • Friday

    Friday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 77. East wind 10 to 15 mph becoming northwest in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 70%.

    High: 77 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 54. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 40%.

    Low: 54 °F

    Chance
    T-storms

Detailed Forecast

Tonight
Mostly cloudy, with a low around 74. South wind 5 to 10 mph.
Tuesday
Cloudy, then gradually becoming mostly sunny, with a high near 92. Heat index values as high as 100. South wind 5 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 71. South wind 5 to 10 mph, with gusts as high as 20 mph.
Wednesday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 89. South wind 5 to 10 mph becoming northeast in the afternoon.
Wednesday Night
A 30 percent chance of showers and thunderstorms, mainly before 1am. Mostly cloudy, with a low around 66. Northeast wind 5 to 10 mph.
Thursday
A 40 percent chance of showers and thunderstorms. Cloudy, with a high near 82. East wind 5 to 10 mph, with gusts as high as 20 mph.
Thursday Night
A 50 percent chance of showers and thunderstorms. Cloudy, with a low around 65. East northeast wind 10 to 15 mph, with gusts as high as 20 mph.
Friday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 77. East wind 10 to 15 mph becoming northwest in the afternoon. Winds could gust as high as 30 mph. Chance of precipitation is 70%.
Friday Night
A chance of showers and thunderstorms before 1am, then a slight chance of showers. Mostly cloudy, with a low around 54. North wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 40%.
Saturday
A 20 percent chance of showers before 1pm. Partly sunny, with a high near 69.
Saturday Night
Partly cloudy, with a low around 49.
Sunday
Sunny, with a high near 76.
Sunday Night
Partly cloudy, with a low around 53.
Monday
Mostly sunny, with a high near 82.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles NNW San Marcos Municipal Airport TX
 29.95°N 97.89°W (Elev. 646 ft)
Last Update:
6:42 pm CDT Apr 27, 2026
Forecast Valid:
9pm CDT Apr 27, 2026-6pm CDT May 4, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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