planning to go to HK Disneyland on May. when's the best time to go?

according to the graph and some of the answers above it is said that it rains a lot in may. but is there a time in may where it is not rainy so we can go to visit? like specific dates or which week would be the best time to go? we will stay in HK for 4 days and plan to spend a lot of time in disneyland. thanks for answering my question.