Planning for the weather is a good way to make your trip to Apia relaxing and enjoyable, especially when you’re splurging. The hottest months are usually March and April with an average temp of 82°F, while the coldest months are August and July with an average of 80°F. The rainiest months in Apia are January, February, December, and November, with each month seeing an average of 14 inches of rainfall.