Summer begins to usher in not only the rainy season, but also the start of typhoon season. As a result, the summer and early fall months are not the best time to visit the island due to the threat of major storms, strong winds, heavy rains and high surf. If visitors do decide to go at this time, it is important to look at an extended forecast and be prepared for cancelled plans in the event of a storm. June is the wettest month for the summer with an average of 237mm of rain over an average of 20 days. July and August are not much drier with an average rainfall amount of 189mm in July and 186mm in August.