Planning for the weather is a good way to make your trip to Manapouri relaxing and enjoyable, especially when you’re splurging. The hottest months are usually January and February with an average temp of 49°F, while the coldest months are July and August with an average of 36°F. The rainiest months in Manapouri are October, September, May, and January, with each month seeing an average of 14 inches of rainfall.