T average Nürnberg from january 2000- november 2009 9,7°C at the airport far outside in the forrest; in City centre Nürnberg 12,5°C, Freiburg 13,2°C as warmest in germany...

But we have one disadvantage: sometimes very cold nights in southern germany in january, that´s bad for teh average! ;-)
Put the january out we have 13-16°C in average in soluthern germany. ;-)

Greets