Planning for the weather is a good way to make your trip to Yonaha relaxing and enjoyable, especially when you're splurging. The hottest months are usually July and August with an average temp of 83°F, while the coldest months are January and February with an average of 68°F. The rainiest months in Yonaha are August, May, September, and June, with each month seeing an average of 11 inches of rainfall.