San Marcos (TX) Weather & Climate: Best Time to Visit

In San Marcos, temperatures differ significantly between summer and winter months. Typically, average maximum daytime temperatures range from a very hot 37°C (99°F) in August to a moderate 17°C (63°F) in the coolest month, January.

Nights vary from 23°C (73°F) in August to around 3°C (37°F) during the colder months.

Check out our detailed temperature page for more information.

Temperature ranges by month

On average, San Marcos receives a reasonable amount of rainfall, with an annual precipitation of 905 mm (36 in). The climate in San Marcos shows significant variation throughout the year. Expect high rainfall in May, the wettest month, with an average of 136 mm (5.4 in) of precipitation over 10 rainy days.

In contrast, the driest month February offers drier and sunnier days, with around 31 mm (1.2 in) of rainfall over 8 rainy days. For more details, please visit our San Marcos Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

For those who appreciate different seasons, San Marcos serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 10.6 hours of sunshine daily, and embrace the darker days in December, offering only 5.1 hours of daily sunlight.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is high throughout the year in San Marcos.

The city experiences its highest humidity in May, reaching 71%. In March, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year