Taking into account the local weather in Fellbach is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually July and August with an average temp of 59°F, while the coldest months are January and February with an average of 32°F. The rainiest months in Fellbach are November, August, May, and June, with each month seeing an average of 10 inches of rainfall.