In terms of precipitation, rainfall in Casper ranges from 0.5 - 2.0 inches per month. May is typically the wettest month, when rainfall can reach 2.0 in. January is typically the driest time to visit Casper when rainfall is around 0.5 in.
If weather is an important factor for your trip to Casper, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 69.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 23.0 F).