Climate almanac
Castle Rock
Colorado, United States · 39.37°, -104.86°
What is the weather like in Castle Rock in September?
In September, Castle Rock is typically 78°F (25°C) during the day and 48°F (9°C) at night. The month brings about 1.2 in (32 mm) of precipitation in total. Snowfall averages about 0.6 in (15 mm) over the month.
- Average high78°F (25°C)
- Average low48°F (9°C)
- Precipitation1.2 in (32 mm)
- Clear or mostly clear days20
- Snowfall0.6 in (15 mm)
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)