August 1: The Warsaw Uprising begins.
August 2: Turkey ends diplomatic and economic relations with Germany. - The First Assembly of ASNOM (the Anti-Fascist Assembly for the People's Liberation of Macedonia) is held in the Prohor Pc(injski monastery.
August 3: The Education Act in the United Kingdom, promoted by Rab Butler, creates a Tripartite System of secondary education.
August 4: A tip from a Dutch informer leads the Gestapo to a sealed-off area in an Amsterdam warehouse, where they find Jewish diarist Anne Frank, her family, and others in hiding. All would die in the Holocaust except for Otto Frank, Anne's father.
August 5: Polish insurgents liberate a German labor camp in Warsaw, freeing 348 Jewish prisoners. - Cowra breakout: Over 500 Japanese prisoners of war attempt a mass breakout from the Cowra camp in Australia. In the ensuing manhunt, 231 Japanese escapees and four Australian soldiers are killed.
August 7: IBM dedicates the first program-controlled calculator, the Automatic Sequence Controlled Calculator (known best as the Harvard Mark I).
August 9: The United States Forest Service and the Wartime Advertising Council release posters featuring Smokey Bear for the first time.
August 12: The Allies capture Florence, Italy. - Operation Pluto: The world's first undersea oil pipeline is laid between England and France.
August 15: Operation Dragoon lands Allies in southern France. The U.S. 45th Infantry Division participates in its fourth assault landing at Sainte-Maxime, spearheading the drive for the Belfort Gap.
August 18: Submarine USS Rasher (SS-269) sinks Teia Maru, Eishin Maru, Teiyu Maru, and carrier Taiyo- from Japanese convoy HI71 in one of the most effective American "wolfpack" attacks of the war.
August 19: An insurrection starts in Paris.
August 20: American forces successfully defeat Nazi forces at Chambois, closing the Falaise Gap. - 168 captured allied airmen, including Phil Lamason, accused of being "terror fliers" by the Gestapo, arrive at Buchenwald concentration camp.
August 21: Dumbarton Oaks Conference (Washington Conversations on International Peace and Security Organization) opens in Washington, D.C.: U.S., British, Chinese, French and Soviet representatives meet to plan the foundation of the United Nations.
August 22: Tsushima Maru, a Japanese unmarked passenger/cargo ship, is sunk by torpedoes launched by the submarine USS Bowfin (SS-287) off Akuseki-jima, killing 1,484 civilians including 767 schoolchildren.
August 23: Ion Antonescu, prime minister of Romania, is arrested and a new government established. Romania leaves the war against the Soviet Union, joining the Allies.
August 24: Liberation of Paris: The Allies enter Paris, successfully completing Operation Overlord. - Japanese vessels attack and sink the submarine USS Harder (SS-257) off Luzon.
August 25: German surrender of Paris: General Dietrich von Choltitz surrenders Paris to the Allies in defiance of Hitler's orders to destroy it. - Maillé massacre: Massacre of 129 civilians (70% women and children) by the Gestapo at Maillé, Indre-et-Loire. - Hungary decides to continue the war together with Germany.
August 29: The Slovak National Uprising against the Axis powers begins.
August 31: The Mad Gasser of Mattoon apparently resumes their mysterious attacks in Mattoon, Illinois for 2 weeks. (source: Wikipedia)