Climate almanac
Altadena
California, United States · 34.19°, -118.13°
What is the weather like in Altadena in September?
In September, Altadena is typically 86°F (30°C) during the day and 64°F (18°C) at night. The month brings about 0.4 in (11 mm) of precipitation in total.
- Average high86°F (30°C)
- Average low64°F (18°C)
- Precipitation0.4 in (11 mm)
- Clear or mostly clear days25
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)