Finnish 27th regiment, now reinforced and renamed 9th division, continues finishing off Soviet 163rd division at Suomussalmi and awaits the arrival of Soviet 44th division from Raate.
Finnish "Group Talvela" (16th Infantry Regiment plus four separate infantry battalions and one battalion of Artillery) attacks Soviet 75th division surrounded at Ägläjärvi.
Red Army continues attacking the Mannerheim Line but lose the initiative in the First Battle of Summa. With temperatures as low as -20C (-4F), the engines of tanks and other vehicles have to be run continuously to prevent freezing up. Fuel runs out, tanks are stranded and Red Army infantry goes forward unsupported. Taipale sector of the Line is noticeably quiet after daily WWI-style artillery/infantry attacks abruptly stopped on Dec 17. From Nov 30, Red Army troops have been marched into a terrible slaughter of accurate Finnish machinegun, mortar, field artillery and coastal battery fire on well-plotted ground.