Thunderstorms and Heavy Rains Across Portions of the Central and Eastern US; Heat Expands to Portions of the East

Widespread showers and thunderstorms, some severe, may produce heavy downpours and flash flooding across much of the eastern and central U.S. Dangerous heat will continue in the Pacific Northwest and expand across portions of the East. Deep tropical moisture and associated thunderstorms will bring heavy rainfall and localized flash flooding across portions of Florida into the central Gulf Coast. Read More >

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Overcast

79°F

26°C

Humidity 97%
Wind Speed S 9 mph
Barometer 29.98 in (1014.1 mb)
Dewpoint 78°F (26°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 16 Jul 1:56 am CDT
Extended Forecast for

4 Miles SSW San Marcos TX

  • Overnight

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

    Low: 75 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, then gradually becoming sunny, with a high near 96. Heat index values as high as 102. South wind 5 to 10 mph, with gusts as high as 20 mph.

    High: 96 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 72. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Low: 72 °F

    Partly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 95. Heat index values as high as 100. South southeast wind around 5 mph.

    High: 95 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 72. Southeast wind around 5 mph.

    Low: 72 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 92. Calm wind becoming south around 5 mph in the morning.

    High: 92 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 75. East southeast wind around 5 mph becoming south after midnight.

    Low: 75 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 94. South wind 5 to 10 mph.

    High: 94 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 75. South southeast wind 5 to 10 mph.

    Low: 75 °F

    Partly Cloudy

Detailed Forecast

Overnight
Mostly cloudy, with a low around 75. South wind around 5 mph.
Wednesday
Mostly cloudy, then gradually becoming sunny, with a high near 96. Heat index values as high as 102. South wind 5 to 10 mph, with gusts as high as 20 mph.
Wednesday Night
Partly cloudy, with a low around 72. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Thursday
Mostly sunny, with a high near 95. Heat index values as high as 100. South southeast wind around 5 mph.
Thursday Night
Partly cloudy, with a low around 72. Southeast wind around 5 mph.
Friday
Mostly sunny, with a high near 92. Calm wind becoming south around 5 mph in the morning.
Friday Night
Partly cloudy, with a low around 75. East southeast wind around 5 mph becoming south after midnight.
Saturday
Mostly sunny, with a high near 94. South wind 5 to 10 mph.
Saturday Night
Partly cloudy, with a low around 75. South southeast wind 5 to 10 mph.
Sunday
Mostly sunny, with a high near 96.
Sunday Night
Partly cloudy, with a low around 75.
Monday
Mostly sunny, with a high near 96.
Monday Night
Partly cloudy, with a low around 75.
Tuesday
Mostly sunny, with a high near 97.
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSW San Marcos TX
 29.81°N 97.96°W (Elev. 676 ft)
1:42 am CDT Jul 16, 2025
2am CDT Jul 16, 2025-6pm CDT Jul 22, 2025
 
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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