Air War
Siege of Leningrad: 60 Ju 87 Stukas make repeated attacks on Russian Baltic Fleet in Kronstadt Harbour, near Leningrad (September 21-24): battleship Marat sunk, battleship Oktyabrskaya Revolutsiya hit by 6 bombs and 2 cruisers damaged.
Western Europe
RAF de Havilland Mosquito flies first (reconnaissance) operation.