Planning for the weather is a good way to make your trip to Guimarães relaxing and enjoyable, especially when you're splurging. The hottest months are usually August and July with an average temp of 68°F, while the coldest months are February and January with an average of 48°F. The rainiest months in Guimarães are October, December, January, and November, with each month seeing an average of 9 inches of rainfall.