DIW expects the German economy to shrink by 1% in Q4 this year
The research institute says that the second hard lockdown in Germany will hit economic output rather harshly during the winter and only if the virus situation stabilises, will the economy return to the recovery path in February.
Essentially, they see January as a given that the virus situation will keep at its current pace or thereabouts as tighter restrictions will still be needed going into the new year.
This just adds to the slightly gloomier prospects going into Q1 next year, as the global virus situation is still not going away any time soon in spite of recent vaccine optimism.