The best time to visit Mitiaro is during the dry season, from April to November, when rainfall is lower and the weather is more settled. The Cook Islands as a whole are tropical, but Mitiaro's small size means it sees less cloud cover than the larger islands. Temperatures hover around 25–27°C year-round.
The wet season (December through March) brings heavier rain and occasional tropical cyclones. Flights from Rarotonga to Mitiaro are on small aircraft and can be disrupted in bad weather; if you have a tight schedule, the dry season is more reliable.
There are no large festivals on Mitiaro, but the annual Constitution Day celebrations in August include inter-island sporting events that occasionally bring visitors from Atiu and Mauke.