Taking into account the local weather in Rabaul is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually May and October with an average temp of 81°F, while the coldest months are August and September with an average of 80°F. The rainiest months in Rabaul are March, April, December, and February, with each month seeing an average of 16 inches of rainfall.