Over a third of the land is intensely cultivated and you'll never travel far without hitting a town. That said, the Bavarian Forest in the south-east is the largest mountain forest in Europe and the Black Forest is big enough to be a bit wild. Forest fauna includes wild pig, fox and deer, but you're never likely to be caught in a stampede. Germany is not prey to dramatic climatic extremes, although there are regional differences. The most reliably good weather is from May to October, with high summer a good bet for shorts and t-shirt, even in the north.
Autumn is a good time to visit Germany.
As the tourist scrum disperses and the forests turn golden, it's not too stifling to be active but still thirsty enough to end the day with a few well-deserved steins. Winter is wet, especially in the south, with snow not usually settling for long except in the high country. That said, the most reliable weather is from May to October. The shoulder periods can bring fewer tourists and surprisingly pleasant weather. There is no special rainy season.