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San Marcos, TX Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for San Marcos, a city in Hays County, Texas.

Today
97°F
Sunny
Sunny, with a high near 97. Heat index values as high as 101. South southeast wind around 5 mph.

7-day forecast for San Marcos

WhenTempForecastWindPrecip
Today 97°F Sunny 5 mph SSE 0%
Tonight 73°F Mostly Clear 0 to 5 mph S 0%
Sunday 98°F Mostly Sunny 0 to 5 mph S 0%
Sunday Night 75°F Partly Cloudy 0 to 5 mph SSE 5%
Monday 97°F Sunny 0 to 5 mph SSE 12%
Monday Night 75°F Mostly Clear 0 to 5 mph S 12%
Tuesday 97°F Slight Chance Rain Showers 0 to 5 mph NE 15%
Tuesday Night 75°F Slight Chance Showers And Thunderstorms 0 to 5 mph ENE 19%
Wednesday 97°F Slight Chance Rain Showers then Mostly Sunny 0 to 5 mph NE 18%
Wednesday Night 74°F Partly Cloudy 0 to 5 mph E 7%
Thursday 96°F Mostly Sunny 0 to 10 mph ENE 6%
Thursday Night 72°F Partly Cloudy 0 to 10 mph ESE 4%
Friday 96°F Mostly Sunny 0 to 5 mph ENE 4%
Friday Night 72°F Partly Cloudy 0 to 5 mph E 4%

Forecast source: National Weather Service (api.weather.gov) for San Marcos (29.872, -97.936). Updated through the day.

Growing snapshot for San Marcos

Last spring frost
Feb 28
First fall frost
Nov 29
Growing season
273 days
Hardiness zone
9a

More local growing data for San Marcos: nearby ZIP 78666 weather · frost dates · planting calendar · Texas frost dates

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Climate data from the nearest NOAA station, San Marcos, Tx (2.1 mi from San Marcos). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.