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In terms of precipitation, rainfall in Boise ranges from 0.2 - 1.6 inches per month. December is typically the wettest month, when rainfall can reach 1.6 in. August is typically the driest time to visit Boise when rainfall is around 0.2 in.
If weather is an important factor for your trip to Boise, 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 75.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 30.2 F).