Taking into account the local weather in Slim River is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually March and February with an average temp of 78°F, while the coldest months are January and February with an average of 77°F. The rainiest months in Slim River are November, December, April, and October, with each month seeing an average of 15 inches of rainfall.