As Germany assembled forces for the invasion of Norway, codenamed Operation Weserübung, "Emden" was allocated to Group 5, which was tasked with seizing Oslo. She joined the group as it began forming in Swinemünde on 12 March. The group consisted of the heavy cruiser , the flagship, the heavy cruiser "Lützow", three torpedo boats, and eight R-type minesweepers. On the night of 5 April, "Emden" and "Blücher" conducted searchlight training to prepare for night operations. The following day, "Emden" embarked 600 soldiers and their equipment in Swinemünde before proceeding to the collection point for the invasion fleet, Strander Bucht outside Kiel. At 03:00 on 8 April, Group 5 left Strander Bucht and steamed to the Oslofjord, where they arrived at midnight.