Travel1000Places.com
Juli/August: between 68 and 86 F (20 - 30 C)
Winter: average around 32 F (0 C)
Year-round:
Summer: explore the city, its parks, its pedestrian friendly downtown, many festivals, beer gardens, ...
Winter: beside discovering the city in winter, which is great to visit castles, museums, and many other things, visitors who like skiing can reach the skiing areas in approx. 1-2 hrs by car (e.g. Garmisch-Patenkirchen).
Munich is located in a moderate climatic zone and therefore has neither an extremely cold winter or an extremely hot summer.
January: between freezing point and 62 F (averages up to 16.9 C)
May: highs in the mid 80's F (averages up to 29.7 C)
June August: highs in the 90's (averages up to 33.7 C)
Precipitation (2002): 1118 mm
Sunshine duration (2002): 1856 hours.