New Castle, in Colorado, United States, is home to roughly 4,700 people in the Mountain Time Zone at 39.6°N latitude.
In 2025, New Castle recorded an average annual temperature of 50°F. The hottest temperatures reached 98°F in July; the coolest were -12°F in January. Total precipitation for the year was 12 inches, with the wettest month being October. Snowfall for the year totaled approximately 11 inches.
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