In terms of precipitation, rainfall in Hakodate ranges from 2.0 - 6.7 inches per month. September is typically the wettest month, when rainfall can reach 6.7 in. February is typically the driest time to visit Hakodate when rainfall is around 2.0 in.
If weather is an important factor for your trip to Hakodate, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 71.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 28.4 F).