About Castle Rock, CO

With a population of around 55,600, Castle Rock sits in Colorado, United States. The city operates in the Mountain Time Zone.

Across a typical year Castle Rock sees about 15 inches of precipitation, with August the wettest month and December the driest. Temperatures range from January lows near 19°F up to July highs around 87°F, averaging 50°F annually — characteristic of a humid continental climate.