Germany is a big country so as would be expected there are certain climate variations from region to region. This having been said the climate throughout Germany is fairly temperate with clear distinct differences between the seasons.
The main differences in temperature between the difference regions of Germany come from the altitudes as opposed to anything else although the East of the country does tend to suffer harsher winters than the West. The Upper Rhine Valley benefits from the mildest temperatures in the country.
Precipitation is high in Germany especially through the summer months with frequent heavy downpours throughout the country.
As a general rule of thumb winter temperatures range from just above freezing in the West to -3°C in the East and anywhere between 20-30°C during the summer months.