In Italy… During the night (October 12-13) the US 5th Army begins its assault on the German Volturno Line. Elements of the British 10th Corps (McCreery) make some progress on the coast but German counterattacks generally hold its attacks. The 3 divisions of US 6th Corps (Lucas), however, push forward. A combination of determined German defenders and poor weather restrict advances to the main roadways.

In the Bismark Archipelago… The US 5th Air Force raids Rabaul, New Britain, with 349 aircraft, dropping 350 tons of bombs. Several defending Japanese aircraft are shot down and 3 destroyers as well as several merchant ships in harbor are damaged.