The Breton climate is mild and temperate. Summer is generally cooler than in other French regions. In winter, sub-zero temperatures are rare. Generally speaking, the weather in Rennes, like everywhere else in Brittany, is quite changeable. It’s not uncommon to have alternating rain and clear skies in the same day, so it’s a good idea to bring a light rain jacket just in case. In autumn, the region is occasionally swept by ocean storms that are more spectacular than they are dangerous. Spring is particularly pleasant, with cool mornings and pleasant afternoon temperatures. Across the entire year, average temperatures in Rennes are around 13 degrees. Excluding heatwaves, summer temperatures fluctuate between 20 and 25 degrees Celsius, or even higher.