In terms of precipitation, rainfall in Derby ranges from 0.0 - 9.8 inches per month. January is typically the wettest month, when rainfall can reach 9.8 in. August is typically the driest time to visit Derby when rainfall is around 0.0 in.
If weather is an important factor for your trip to Derby, use this chart to help with planning. For those seeking warmer temperatures, December is the ideal time of year to visit, when temperatures reach an average of 89.6 F. Travelers looking to avoid the cold should look outside of July, when temperatures are typically at their lowest (around 71.6 F).