Planning for the weather is a good way to make your trip to Alotau relaxing and enjoyable, especially when you're splurging. The hottest months are usually January and February, with an average temperature of 27°C, while the coldest months are August and July, with an average of 25°C. The rainiest months in Alotau are January, February, March and December, with each month seeing an average of 371 mm of rainfall.