Munich has a very moderate historic climate, as you can see from the temperature chart below.
May through September Munich's most popular months for travel, but October, with oktoberfest celebrations, and April can be good as well. Summers can occasionally be wet, with thunderstorms not uncommon. The cloud cover can give photographers those dramatic skies that help make a photograph memorable.
Winter in Munich is cold, but snow tends not to be so heavy in the city.
Munich is a great year-around destination. If you don't mind the weather and some below freezing temperatures, November through March puts you right in the cultural season if you don't mind the cold and sunless skies.
The charts below show the historic high and low temperatures in Munich and the month by month precipitation chart below that.