WHEN TO GO
The best time to visit Switzerland, Germany and France in April to September.
France is perfect all through the year but during spring, especially during April to June, its perfect as the sun is pleasant and the warmth is very welcoming.
April - September is generally the most recommended period to visit Switzerland.
The ideal time to travel to Germany is during the spring/summer season, between the months of April and August and weather's very pleasant and you can spend longer time outdoors exploring the many beautiful sights. You can also visit the place during autumn which is between September-November. And if you want to absolutely experience the cold then it's the winter months.