Planning for the weather is a good way to make your trip to Kagoshima relaxing and enjoyable, especially when you're splurging. The hottest months are usually August and July with an average temp of 77°F, while the coldest months are January and February with an average of 50°F. The rainiest months in Kagoshima are June, July, May, and September, with each month seeing an average of 16 inches of rainfall.