Planning for the weather is a good way to make your trip to Manihiki relaxing and enjoyable, especially when you're splurging. The hottest months are usually April and May, with an average temperature of 28°C, while the coldest months are August and September, with an average of 28°C. The rainiest months in Manihiki are January, February, March and December, with each month seeing an average of 279 mm of rainfall.