Climate almanac
Mill Valley
California, United States · 37.91°, -122.54°
What is the weather like in Mill Valley in September?
In September, Mill Valley is typically 75°F (24°C) during the day and 57°F (14°C) at night. The month brings about 0.2 in (4 mm) of precipitation in total.
- Average high75°F (24°C)
- Average low57°F (14°C)
- Precipitation0.2 in (4 mm)
- Clear or mostly clear days18
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)