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

Dangerous Heat in a Couple of Locations; Active Monsoon

Dangerous heat continues in a couple of locations today. In the Pacific Northwest to the central Valley of California and across the Gulf Coast region from the western Florida Panhandle to eastern Texas. Meanwhile, the monsoon threat of heavy rainfall and flooding will be possible in the Four Corners region and west Texas today, with a more significant threat on Friday in Arizona and New Mexico. Read More >

Hazardous Weather Conditions

Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Mostly Cloudy

99°F

37°C

Humidity 33%
Wind Speed SW 9 mph
Barometer 29.93 in (1012.2 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 17 Aug 4:56 pm CDT
Extended Forecast for

San Marcos TX

  • Tonight

    Tonight: Partly cloudy, with a low around 77. South southwest wind 5 to 10 mph.

    Partly Cloudy

    Low: 77 °F

  • Thursday

    Thursday: A 50 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 100. Heat index values as high as 103. Southwest wind 5 to 10 mph becoming south southeast in the afternoon. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Mostly Sunny
    then Chance
    T-storms

    High: 100 °F

  • Thursday
    Night

    Thursday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 74. North northeast wind 5 to 10 mph becoming south after midnight. Winds could gust as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Chance
    T-storms

    Low: 74 °F

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93. South wind 5 to 10 mph becoming east southeast in the afternoon.

    Chance
    Showers then
    Chance
    T-storms

    High: 93 °F

  • Friday
    Night

    Friday Night: Partly cloudy, with a low around 74. East southeast wind 5 to 10 mph becoming south after midnight.

    Partly Cloudy

    Low: 74 °F

  • Saturday

    Saturday: Mostly sunny, with a high near 95. South wind 5 to 15 mph, with gusts as high as 20 mph.

    Mostly Sunny

    High: 95 °F

  • Saturday
    Night

    Saturday Night: Partly cloudy, with a low around 75. South wind 10 to 15 mph decreasing to 5 to 10 mph after midnight. Winds could gust as high as 20 mph.

    Partly Cloudy

    Low: 75 °F

  • Sunday

    Sunday: A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 94. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Partly Sunny
    then Chance
    Showers

    High: 94 °F

  • Sunday
    Night

    Sunday Night: Mostly cloudy, with a low around 76. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.

    Mostly Cloudy

    Low: 76 °F

Detailed Forecast

Tonight
Partly cloudy, with a low around 77. South southwest wind 5 to 10 mph.
Thursday
A 50 percent chance of showers and thunderstorms after 1pm. Mostly sunny and hot, with a high near 100. Heat index values as high as 103. Southwest wind 5 to 10 mph becoming south southeast in the afternoon. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Thursday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 74. North northeast wind 5 to 10 mph becoming south after midnight. Winds could gust as high as 20 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
A 40 percent chance of showers and thunderstorms. Mostly sunny, with a high near 93. South wind 5 to 10 mph becoming east southeast in the afternoon.
Friday Night
Partly cloudy, with a low around 74. East southeast wind 5 to 10 mph becoming south after midnight.
Saturday
Mostly sunny, with a high near 95. South wind 5 to 15 mph, with gusts as high as 20 mph.
Saturday Night
Partly cloudy, with a low around 75. South wind 10 to 15 mph decreasing to 5 to 10 mph after midnight. Winds could gust as high as 20 mph.
Sunday
A 30 percent chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 94. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Sunday Night
Mostly cloudy, with a low around 76. South southeast wind 5 to 15 mph, with gusts as high as 20 mph.
Monday
A slight chance of showers, then a chance of showers and thunderstorms after 1pm. Partly sunny, with a high near 95. Chance of precipitation is 30%.
Monday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 75.
Tuesday
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 94.
Tuesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 74.
Wednesday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 92.
Click Map For Forecast
Disclaimer
Map Legend
Point Forecast:
San Marcos TX
 29.88°N 97.94°W (Elev. 577 ft)
Last Update:
2:10 pm CDT Aug 17, 2022
Forecast Valid:
5pm CDT Aug 17, 2022-6pm CDT Aug 24, 2022
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation