At the outbreak of World War II on 1 September 1939, Nürnberg was assigned to the blockade force that was intended to prevent the Polish Navy from escaping from the Baltic.
Despite the Germans' efforts, several Polish destroyers and submarines escaped to Britain, where they continued the war.
On 3 September, Nürnberg and the rest of the cruisers were withdrawn to the North Sea to lay a series of defensive minefields to protect the German coastline.
She returned to the Baltic for training exercises in October.
The following month, she was transferred back to the North Sea, where she was tasked with escorting destroyers laying minefields off the British coast.
On 4–6 December, the ship conducted a mining operation off Kristiansand, Norway.

On 13 December, while escorting a group of destroyers returning from a mine-laying operation off the British coast, the Royal Navy submarine HMS Salmon launched a spread of torpedoes at the German flotilla.
Two torpedo tracks were spotted heading toward Nürnberg, and the ship turned hard to port in an attempt to evade them.
One passed harmlessly ahead of the ship, but the second struck her in the bow.
Nürnberg reduced speed to 12 knots (22 km/h; 14 mph) to allow her crew to inspect the damage, when three more torpedo tracks were spotted to port.
The ship immediately accelerated to full speed and turned to starboard; the torpedoes exploded in the cruiser's wake.
The hit caused some minor flooding and minimal damage, but her watertight bulkheads held.
The Germans spotted Salmon and briefly engaged her with Nürnberg's rearmost main battery turret, but to no effect.
Nürnberg thereafter got underway at a speed of 18 knots (33 km/h; 21 mph) and made for port.
HMS Ursula unsuccessfully attacked the damaged cruiser the following day, just before she entered the Kiel Canal at Brunsbüttel.
After arriving in Kiel, Nürnberg went into drydock at Deutsche Werke for repairs, which lasted until April 1940.

In early June 1940, Nürnberg's commander, Kapitän zur See (KzS) Otto Klüber, was informed that the ship would not participate in Operation Juno, a sortie by the battleships Gneisenau and Scharnhorst.
Instead, she was transferred to Norway, departing Kiel on 10 June under the escort of the torpedo boats Falke and Jaguar.
On 12 June, the torpedo boats were sent to Stavanger for fuel, and in the meantime, Nürnberg steamed a zig-zag course at 27 knots (50 km/h; 31 mph) to evade any submarines that might be in the area.
The following day, the 2nd Minesweeper Flotilla took over her escort duty off Trondheim.
On 17 June, Nürnberg reached Narvik, which was to be her base for the next month.
During this period, one of her Arado Ar 196 floatplanes unsuccessfully attacked a British submarine.
This was the only action the ship saw while in Norway.
On 25 July, Nürnberg and several destroyers and torpedo boats escorted the damaged battleship Gneisenau, which had been torpedoed by a British submarine, from Trondheim, Norway, to Kiel.
The flotilla arrived in Kiel on 28 July.

On 8 August, KzS Leo Kreisch replaced Klüber as the ship's commander.
Nürnberg spent the rest of the year in the Baltic.
The Italian Admiral Mavagini visited the ship while she was in Gotenhafen in September.
A short refit was conducted at Deutsche Werke in October and November.
On 15 February 1941, she was reclassified as a training cruiser and assigned to the Fleet Training Squadron, along with the other surviving light cruisers.
These ships were tasked with training the crews for the U-boat arm, which was expanding rapidly to wage the Battle of the Atlantic.
At the start of this period, many of her crewmen were themselves transferred to the U-boat fleet.
After the outbreak of war with the Soviet Union in June 1941, Nürnberg was reassigned to the Baltic Fleet, which was centered on the new battleship Tirpitz.
After it became clear that the Soviet Baltic Fleet did not intend to sortie, the German ships were dispersed.
Nürnberg returned to her training duties for the remainder of the year.
Another refit was conducted in January 1942; during this
At the outbreak of World War II on 1 September 1939, Nürnberg was assigned to the blockade force that was intended to prevent the Polish Navy from escaping from the Baltic. Despite the Germans' efforts, several Polish destroyers and submarines escaped to Britain, where they continued the war. On 3 September, Nürnberg and the rest of the cruisers were withdrawn to the North Sea to lay a series of defensive minefields to protect the German coastline. She returned to the Baltic for training exercises in October. The following month, she was transferred back to the North Sea, where she was tasked with escorting destroyers laying minefields off the British coast. On 4–6 December, the ship conducted a mining operation off Kristiansand, Norway.
On 13 December, while escorting a group of destroyers returning from a mine-laying operation off the British coast, the Royal Navy submarine HMS Salmon launched a spread of torpedoes at the German flotilla. Two torpedo tracks were spotted heading toward Nürnberg, and the ship turned hard to port in an attempt to evade them. One passed harmlessly ahead of the ship, but the second struck her in the bow. Nürnberg reduced speed to 12 knots (22 km/h; 14 mph) to allow her crew to inspect the damage, when three more torpedo tracks were spotted to port. The ship immediately accelerated to full speed and turned to starboard; the torpedoes exploded in the cruiser's wake. The hit caused some minor flooding and minimal damage, but her watertight bulkheads held. The Germans spotted Salmon and briefly engaged her with Nürnberg's rearmost main battery turret, but to no effect. Nürnberg thereafter got underway at a speed of 18 knots (33 km/h; 21 mph) and made for port. HMS Ursula unsuccessfully attacked the damaged cruiser the following day, just before she entered the Kiel Canal at Brunsbüttel. After arriving in Kiel, Nürnberg went into drydock at Deutsche Werke for repairs, which lasted until April 1940.
In early June 1940, Nürnberg's commander, Kapitän zur See (KzS) Otto Klüber, was informed that the ship would not participate in Operation Juno, a sortie by the battleships Gneisenau and Scharnhorst. Instead, she was transferred to Norway, departing Kiel on 10 June under the escort of the torpedo boats Falke and Jaguar. On 12 June, the torpedo boats were sent to Stavanger for fuel, and in the meantime, Nürnberg steamed a zig-zag course at 27 knots (50 km/h; 31 mph) to evade any submarines that might be in the area. The following day, the 2nd Minesweeper Flotilla took over her escort duty off Trondheim. On 17 June, Nürnberg reached Narvik, which was to be her base for the next month. During this period, one of her Arado Ar 196 floatplanes unsuccessfully attacked a British submarine. This was the only action the ship saw while in Norway. On 25 July, Nürnberg and several destroyers and torpedo boats escorted the damaged battleship Gneisenau, which had been torpedoed by a British submarine, from Trondheim, Norway, to Kiel. The flotilla arrived in Kiel on 28 July.
On 8 August, KzS Leo Kreisch replaced Klüber as the ship's commander. Nürnberg spent the rest of the year in the Baltic. The Italian Admiral Mavagini visited the ship while she was in Gotenhafen in September. A short refit was conducted at Deutsche Werke in October and November. On 15 February 1941, she was reclassified as a training cruiser and assigned to the Fleet Training Squadron, along with the other surviving light cruisers. These ships were tasked with training the crews for the U-boat arm, which was expanding rapidly to wage the Battle of the Atlantic. At the start of this period, many of her crewmen were themselves transferred to the U-boat fleet. After the outbreak of war with the Soviet Union in June 1941, Nürnberg was reassigned to the Baltic Fleet, which was centered on the new battleship Tirpitz. After it became clear that the Soviet Baltic Fleet did not intend to sortie, the German ships were dispersed. Nürnberg returned to her training duties for the remainder of the year. Another refit was conducted in January 1942; during this 
German cruiser Nürnberg