Tanzania is a tropical country, and temperatures are relatively consistent year-round, at about 77°F–86°F (25°C–30°C) on the lowlands and at the coast, and around 59°F–68°F (15°C–20°C) in the highlands. The biggest variables are altitude and rainfall. Tanzania has two main rainy seasons, the short rains and the long rains. The long rains start in late March and continue into May. Although May was traditionally a very wet month, it has been drier than it used to be in recent years. While you should still expect it to rain on most days in May, it might not rain all day, every day.
Crowds & Costs
May is the low season for travel to Tanzania. The wet weather can disrupt all kinds of activities, from beach vacations to safaris, and it can be difficult to track and follow wildlife when there's a lot of rain and the roads are disrupted. Many lodges across the country shut for this season, but you may get a good deal at those that do remain open.
Chat with a local specialist who can help organize your trip.
Where to Go
If you're passing through Dar es Salaam, a major coastal city in the northeast, on your way to Tanzania's natural attractions, it's worth spending some time here. This is especially so when the weather isn't so great. With Arab, African, Indian, and British colonial-era influences, there are interesting cultural attractions to enjoy in the city. The open-air Village Museum is a branch of the National Museum and has recreations of Tanzanian villages, with folk dancing shows.
What to Do
Many people consider bird watching to be at its best in Tanzania in the long rainy season, so if you're a keen bird watcher, May is a great time to visit. Some top bird-watching destinations are the Mount Meru area, Tarangire National Park, Lake Manyara National Park, Ngorongoro Conservation Area, and the Serengeti National Park. A huge number of species can be spotted, including crowned hawk-eagles, cinnamon-chested bee-eaters, Rueppell's robin-chas, the very rare Beesley's larks, ashy starlings, yellow-collared lovebirds, rufous-tailed weavers, and much more.
You may also want to venture to the Usambara Mountains in northeastern Tanzania, part of an ancient arc of crystalline mountains. The montane forest, woodlands, and patches of intact (un-deforested) forest in the West Usambaras provide habitats for a vast range of birds, including the endemic Usambara weaver.
Events in May
Mzalendo Halisi Music Festival, Dar es Salaam. This two-day music festival features Tanzanian music and dance, as well as art and cultural exhibits.
Ruaha Marathon, Iringa. Thousands of runners and observers are attracted to the southern highlands in the third week of May for this race.