Gisenyi in September

June through August brings dry weather and clear skies, perfect for volcano hikes and lake activities. December through February offers another dry window, though it gets busier around Christmas and New Year. The rains from March to May turn everything green but make volcano treks muddy and sometimes dangerous. September to November sees short rains that come and go quickly — you might get lucky with clear days, or you might spend a week indoors. Lake Kivu stays warm year-round, so swimming is always possible. The best time really depends on what you're after: dry season for hiking, wet season for cheaper accommodation and fewer crowds. But here's what the guidebooks won't tell you — even the rainy season has its charms when mist rolls across the lake at dawn.