Lisbon Portugal Weather and Historic Climate
Lisbon's weather is moderated by it's location on the Atlantic, and you won't see any extremes in the graphs below. Although mild, winter months tend to be rainy.
Lisbon - When To Go
Spring and early Fall are the best times to visit. June is optimal, as the festival season is heating up in Lisbon. August can be hot. Late September through October is also a good bet. If you must go in Summer, reserve your lodging in advance, as this is the major vacation time in Europe
Lisbon historic Temperatures and Precipitation
The chart below shows the historic high and low temperatures in Lisbon, with the rainfall below that.