Taking into account the local weather in Demak is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually September and October with an average temp of 82°F, while the coldest months are July and August with an average of 81°F. The rainiest months in Demak are January, December, February, and March, with each month seeing an average of 16 inches of rainfall.