Record cold weather strikes Finland. The mercury drops to −43°C (−45°F) on the Karelian Isthmus and −45°C (−49°F) further North in Summa. Even at noon it is −39°C (−38°F) in Taipale and Lake Lagoda freezes over completely creating new problems for the Finns. Soviet troops freeze to death while Finns stay warm in heated tents and mobile saunas. However, frostbite leads to thousands of casualties on both sides.
The German Enigma code is first broken by Polish and French cipher experts at Poste de Commandement Bruno (Chateau de Vignolles at Gretz-Armainvillers, 40 km northeast of Paris) and Dilly Knox’s team at Government Code and Cypher School (Bletchley Park, England), using a German transmission intercepted by the Poles on 28 October 1939.
U-25 torpedo British steamer SS Polzella near the Shetland Isles, Scotland. U-25 shells and torpedoes Norwegian ship SS Enid attempting to rescue Polzella’s crew of 36 (they all perish in the water). Enid’s crew of 16 takes to the lifeboats and are rescued by British trawler SS Granada and Danish merchant SS Kina.