Taking the local weather in Tainan into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually July and August, with an average temperature of 29°C, while the coldest months are January and February, with an average of 20°C. The rainiest months in Tainan are August, June, May and July, with each month seeing an average of 418 mm of rainfall.