Planning for the weather is an important factor for making your trip to Shizuoka a success, especially when you're splurging. The hottest months are usually August and July with an average temp of 74°F, while the coldest months are January and February with an average of 44°F. The rainiest months in Shizuoka are July, June, September, and April, with each month seeing an average of 14 inches of rainfall.