Of course 21°C are unusual warm for november, even in Freiburg but 13°C-15°C like here in Nürnberg is normal... ;-) Record for Nürnberg in November is 19,1°C.

Southern Germany is more cold in winter nights than Hamburg but the warm summer, spring and fall days compense that fact more...

What a luck. ;-)

Nevertheless plams grow better in Hamburg, but i don´t like the weather most of the year there.

Greets