Taking the local weather in Kastam into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually March and May, with an average temperature of 27°C, while the coldest months are January and February, with an average of 26°C. The rainiest months in Kastam are November, October, May and September, with each month seeing an average of 324 mm of rainfall.