Texas · NWS EWX office

San Marcos, TX weather

It is 68°F and cloudy at San Marcos, San Marcos Municipal Airport as of Oct 28, 1:15 AM CDT. Overnight: Partly Cloudy, low near 63°F, 2% chance of precipitation. Forecast from the National Weather Service, issued Oct 28, 12:42 AM CDT.

Updated Oct 28, 1:20 AM CDT (snapshot)

Current conditions

Temperature

68°F

Cloudy

Wind

Calm

Humidity 83% · dew point 63°F

Pressure · visibility

30.16 inHg

Visibility 10 mi

Observed at San Marcos, San Marcos Municipal Airport (KHYI), Oct 28, 1:15 AM CDT. Station readings can lag or be missing.

Alerts for this area

No active NWS alerts cover the San Marcos forecast zone right now.

Around the NWS EWX forecast area

No active alerts in zones served by the EWX office near San Marcos.

From the alert snapshot of Oct 28, 2026, 2:15 AM EDT. Texas has 2 active alerts: see them all.

For official warnings, check weather.gov and your local authorities. OpenForecast repeats National Weather Service alerts and may be delayed or incomplete. Follow instructions from emergency officials.

Next 24 hours

Hourly forecast for San Marcos (local time)
TimeTempForecastPrecip. chanceWind
Wed 1 AM66°FPartly Cloudy2% 0 mph
Wed 2 AM66°FPartly Cloudy2% 0 mph
Wed 3 AM66°FPartly Cloudy2% 0 mph
Wed 4 AM65°FPartly Cloudy2% 0 mph
Wed 5 AM64°FPartly Cloudy2% 0 mph
Wed 6 AM64°FPartly Sunny2% 0 mph
Wed 7 AM64°FSlight Chance Rain Showers22% 0 mph
Wed 8 AM64°FSlight Chance Rain Showers22% 0 mph
Wed 9 AM67°FSlight Chance Rain Showers22% 0 mph
Wed 10 AM72°FSlight Chance Showers And Thunderstorms17%E 5 mph
Wed 11 AM75°FSlight Chance Showers And Thunderstorms17%E 5 mph
Wed 12 PM78°FSlight Chance Showers And Thunderstorms17%ESE 5 mph
Wed 1 PM81°FSlight Chance Showers And Thunderstorms21%SE 5 mph
Wed 2 PM83°FSlight Chance Showers And Thunderstorms21%SE 5 mph
Wed 3 PM83°FSlight Chance Showers And Thunderstorms21%SE 5 mph
Wed 4 PM84°FSlight Chance Showers And Thunderstorms24%SE 5 mph
Wed 5 PM83°FSlight Chance Showers And Thunderstorms24%SE 5 mph
Wed 6 PM82°FSlight Chance Showers And Thunderstorms24%SE 5 mph
Wed 7 PM79°FMostly Cloudy8%SE 5 mph
Wed 8 PM75°FMostly Cloudy8%SE 5 mph
Wed 9 PM73°FPartly Cloudy8%SE 5 mph
Wed 10 PM72°FMostly Cloudy1%SE 5 mph
Wed 11 PM71°FMostly Cloudy1%SSE 5 mph
Thu 12 AM70°FMostly Cloudy1%SSE 5 mph

Hourly values come from the NWS gridded forecast for the 2.5 km grid square that covers the city's center point. Conditions elsewhere in San Marcos can differ.

7-day forecast

Overnight

Low 63°F

Partly cloudy, with a low around 63. East southeast wind around 0 mph.

Wednesday

High 85°F·Low 66°F

A slight chance of rain showers between 7am and 10am, then a slight chance of showers and thunderstorms. Partly sunny, with a high near 85. East wind 0 to 5 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

Wednesday Night: A slight chance of showers and thunderstorms before 7pm. Mostly cloudy, with a low around 66. Southeast wind 0 to 5 mph. Chance of precipitation is 20%.

Thursday

High 81°F·Low 64°F

A chance of showers and thunderstorms after 7am. Mostly cloudy, with a high near 81. East southeast wind 0 to 5 mph. Chance of precipitation is 30%.

Thursday Night: A chance of showers and thunderstorms before 1am. Cloudy, with a low around 64. East southeast wind around 5 mph. Chance of precipitation is 30%.

Friday

High 79°F·Low 63°F

A chance of rain showers between 7am and 1pm. Mostly cloudy, with a high near 79. Southeast wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

Friday Night: A slight chance of showers and thunderstorms after 7pm. Mostly cloudy, with a low around 63. Southeast wind 0 to 5 mph. Chance of precipitation is 20%.

Saturday

High 84°F·Low 64°F

A slight chance of showers and thunderstorms before 7am. Partly sunny, with a high near 84. South wind 0 to 5 mph. Chance of precipitation is 20%.

Saturday Night: Partly cloudy, with a low around 64. East wind around 0 mph.

Sunday

High 85°F·Low 67°F

Partly sunny, with a high near 85.

Sunday Night: Mostly cloudy, with a low around 67.

Monday

High 85°F·Low 63°F

A slight chance of rain showers before noon. Partly sunny, with a high near 85. Chance of precipitation is 20%.

Monday Night: A chance of showers and thunderstorms. Partly cloudy, with a low around 63. Chance of precipitation is 30%.

Tuesday

High 79°F

A chance of rain showers. Mostly sunny, with a high near 79.

Nearby cities

Larger cities in the area

Other cities in Hays County

See every city we cover in Texas, or check all active alerts.

About this forecast

Forecast office
San Marcos is served by the National Weather Service EWX forecast office, forecast zone TXZ191, county zone TXC209.
Location used
The Census Bureau's internal point for San Marcos (29.8736, -97.9367), in Hays County. Population: 74,316 (2024 estimate), number 56 of the 154 Texas cities on this site.
Radar
Nearest NWS radar: KEWX. View it on radar.weather.gov.

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Sources

  • Forecast, hourly forecast, observations and alerts: National Weather Service API, api.weather.gov/points/29.8736,-97.9367 (forecast issued Oct 28, 12:42 AM CDT).
  • Official forecast page: forecast.weather.gov.
  • City location and population: U.S. Census Bureau, Vintage 2024 population estimates and 2024 Gazetteer files.
  • Snapshot taken Oct 28, 2026. The NWS and Census Bureau do not endorse OpenForecast.

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