The climate in Wiesbaden is classified as a temperate oceanic one. The summers are generally warm while the winters are quite cold. Rainfall is prevalent throughout the year, though it is neither too heavy nor present for longer durations. The average annual temperature ranges around 10 degree Celsius.
Wiesbaden is one city that can probable be visited anytime of the year. If you want to witness snowfalls then head over to the city in the Winters, summers are great but can get a humid. But, undeniably Spring and Fall season is the best time to visit Wiesbaden. This is because the weather is too awesome to not be experienced. But be warned, as this is also the peak season and the city is very crowded.