Toamasina sits on Madagascar's east coast and receives some of the heaviest rainfall in the country — around 3,000 mm a year, much of it falling between November and April. The wet season is not simply rainy but actively dangerous: this is the cyclone belt, and severe tropical cyclones make landfall near Toamasina more frequently than almost anywhere else in the Indian Ocean. Cyclone Geralda in 1994 and Cyclone Giovanna in 2012 both caused devastating damage to the city and surrounding region. Travelling in this period is possible but requires flexibility — roads become impassable, ferry and coastal boat services are suspended, and the Ivoloina park track turns to mud.
The dry season runs from May to October. Temperatures remain warm (25–28°C) and the trade winds off the Indian Ocean keep the humidity manageable. June and July are the coolest months and the most comfortable for walking. September and October are excellent: dry, warm, and with wildlife activity at its peak in the parks.
The Betsimisaraka New Year (Alahamady Be) falls in March, when the wet season is still in full force, but the celebration is worth seeing if you happen to be in the region.