Castle Rock (CO) Weather & Climate: Best Time to Visit

The climate in Castle Rock is known for significant temperature differences throughout the year, making the weather dynamic. On average, daytime temperatures range from a comfortable 30°C (86°F) in July to a chilly 6°C (43°F) in December.

Nighttime temperatures range from 14°C (57°F) in July to -9°C (16°F) in December.

Check out our detailed temperature page for more information.

Temperature ranges by month

Castle Rock has a relatively dry climate with low precipitation, averaging 475 mm (19 in) of rain/snowfall annually. The seasons in Castle Rock bring significant changes in precipitation. The wettest month, July, receives moderate rainfall, with an average of 79 mm (3.1 in) of precipitation. This rainfall is distributed across 15 rainy days.

In contrast, the driest month, January, experiences much less snowfall, totaling 14 mm (0.6 in) over 5 snowy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Castle Rock Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

In Castle Rock, summer days are longer and more sunny, with daily sunshine hours peaking at 10.8 hours in July. As the darker season arrives, the brightness of the sun becomes less. November sees a soft sun for only 6.5 hours per average day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is moderate throughout the year in Castle Rock.

The city experiences its highest humidity in December, reaching 56%. In July, the humidity drops to its lowest level at 46%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year