July in Castle Rock averages a daily high of 30.4°C with nights around 13.6°C. Expect roughly 8.7 wet days totalling 63.1mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Castle Rock is May–June.
Based on CASTLE ROCK, CO US (1.7km), 1995–2024. 30 years of July data.