Santa Rosa Weather in September

September in Santa Rosa brings very high temperatures around 31°C (88°F) during the day, dropping to 25°C (77°F) at night, and as part of the rainy season, heavy rainfall is common.

Rainfall in Santa Rosa in September

As part of the rainy season, Santa Rosa sees around 19 days of rain in September, with an average of 385 mm (15 in). Showers during the rainy season tend to be heavy and can come down intensely. An umbrella is often not enough, so a poncho or waterproof jacket is a better choice.

Temperature in Santa Rosa in September

Temperatures in Santa Rosa in September top out at 31°C (88°F) and drop to 25°C (77°F) overnight. The hottest part of the day is usually in the afternoon, so lighter clothing can help you stay comfortable. With overnight lows of 25°C (77°F), evenings and nights remain warm. Light clothing and an open window or fan can help you sleep comfortably.

Sunshine in Santa Rosa in September

The area enjoys a balanced 132 hours of sunlight, ensuring it's neither too rainy nor too sunny.

September in Santa Rosa can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.