In terms of precipitation, rainfall in Hachijo ranges from 6.7 - 20.1 inches per month. October is typically the wettest month, when rainfall can reach 20.1 in. July is typically the driest time to visit Hachijo when rainfall is around 6.7 in.
If weather is an important factor for your trip to Hachijo, 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 77.0 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 50.0 F).