January
January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics.
January 3 – Albert Einstein begins doing research at the California Institute of Technology, along with astronomer Edwin Hubble.
January 4 – German pilot Elly Beinhorn begins her flight to Africa.
January 6 – Thomas Edison submits his last patent application.
January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia.
January 25 – Mohandas Gandhi is again released from imprisonment in India.[citation needed]
January 27 – Pierre Laval forms a government in France.
January 30 – Release of the movie City Lights starring Charlie Chaplin.
February
February 3 – Hawke's Bay earthquake: Much of the New Zealand cities of Napier and Hastings are destroyed in an earthquake measuring 7.9 on the Richter scale killing 256 people.
February 4 – Soviet leader Joseph Stalin gives speech calling for rapid industrialization, arguing that only strong industrialized countries will win wars while "weak" nations are "beaten". Stalin states : "We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it, or they will crush us." Intensification of the First Five-Year Plan in the Soviet Union for industrialization and collectivization of agriculture.
February 10 – Official inauguration ceremonies for New Delhi as the capital of India begin. February 11 – National Socialist (NSDAP) and National Party (DNVP) members walk out of the German Reichstag in protest against changes in the parliament's protocol intended to limit heckling.
February 12 – Vatican Radio first broadcasts.
February 14 – The original film version of Dracula with Bela Lugosi is released in the United States.
February 16 – Pehr Evind Svinhufvud is elected president of Finland.
February 20 – California gets the go-ahead by the United States Congress to build the San Francisco–Oakland Bay Bridge.
February 21 – Peruvian revolutionaries hijack a Ford Trimotor aeroplane and demand that the pilot drop propaganda leaflets over Lima.
February 10: New Delhi becomes India's capital
February 21: Ford Trimotor hijacked
March
March 1 – The USS Arizona is placed back in full commission after a refit.
March 1 – Sir Oswald Mosley founds the New Party as a breakaway from the Labour Party in the United Kingdom.
March 3 – The Star-Spangled Banner is adopted as the United States' National anthem.
March 5 – The British viceroy of India and Mohandas Gandhi sign the Gandhi–Irwin Pact.
March 7 – The new House of Representatives opens in Helsinki, Finland.
March 11 – The Ready for Labour and Defence of the USSR programme, abbreviated as GTO, is introduced in the Soviet Union.
March 17 – Nevada legalizes gambling.
March 19 – Westminster St George's by-election in the U.K. results in the victory of the Conservative candidate Duff Cooper. The by-election has been treated virtually as a referendum on the leadership of the Conservative leader Stanley Baldwin, and Duff Cooper's victory ends the campaign by the press barons Lord Beaverbrook and Viscount Rothermere to oust Baldwin.
March 23 – Indian revolutionary leaders Bhagat Singh, Shivaram Rajguru and Sukhdev Thapar are hanged for conspiracy to murder in the British Raj.
March 25 – The Scottsboro Boys are arrested in Alabama and charged with rape.
March 27 – British writer Arnold Bennett dies of typhoid in London shortly after returning from a visit to Paris, where he drank local water to prove it was safe.
March 31 – An earthquake destroys Managua, Nicaragua, killing 2,000 people.
April
April 1 – The Second Encirclement Campaign against Jiangxi Soviet in China is launched by the Kuomintang government to destroy the Communist forces in Jiangxi province.
April 6 – The Portuguese government declares martial law in Madeira and in the Azores because of an attempted military takeover in Funchal.
April 9 – Argentinian anarchist Severino Digiovanni is executed.
April 12 – Municipal elections in Spain, which are treated as a virtual referendum on the monarchy, result in the triumph for the republican parties.
April 14 – The Second Spanish Republic is proclaimed in Madrid.
April 15 – The Castellammarese War ends with the assassination of Joe "The Boss" Masseria, briefly leaving Salvatore Maranzano as capo di tutti i capi ("boss of all bosses") and undisputed ruler of the American Mafia. Maranzano is himself assassinated less than 6 months later, leading to the establishment of the Five Families.
April 22 – Austria, Britain, Denmark, Germany, Italy, Sweden and the USA recognize the Spanish Republic.
May
May 1: Empire State Building is completed.
May 1 – Construction of the Empire State Building is completed in New York City.
May 4 – Kemal Atatürk is re-elected president of Turkey.
May 5 – İsmet İnönü forms new government in Turkey. (7th government)
May 11 – The Creditanstalt, Austria's largest bank, goes bankrupt, beginning the banking collapse in Central Europe that causes a worldwide financial meltdown.
May 13 – Paul Doumer is elected president of France.
May 15 – The Chinese Communists inflict a sharp defeat on the Kuomintang forces.
May 31 – The Second Encirclement Campaign against Jiangxi Soviet ends in defeat of the Kuomintang.
June
June 5 – German Chancellor Dr. Heinrich Brüning visits London, where he warns the British Prime Minister Ramsay MacDonald that the collapse of the Austrian banking system, caused by the bankruptcy of the Creditanstalt, has left the entire German banking system on the verge of collapse.
June 12 – English cricketer Charlie Parker equals J. T. Hearne's record for the earliest date to reach 100 wickets.
June 14 – The overloaded pleasure craft Saint-Philibert, carrying trippers home to Nantes from the Île de Noirmoutier, sinks at the mouth of the river Loire in France; over 450 drown.
June 19
In an attempt to stop the banking crisis in Central Europe from causing a worldwide financial meltdown, U.S. President Herbert Hoover issues the Hoover Moratorium.
The Geneva Convention (1929) relative to the treatment of prisoners of war enters into force.
June 23–July 1 – Wiley Post and Harold Gatty accomplish the first round-the-world flight in a single-engine plane, flying eastabout from Roosevelt Field, New York, in 8 days, 15 hours, 51 minutes.
July
July – John Haven Emerson of Cambridge, Massachusetts perfects his negative pressure ventilator ("iron lung") just in time for the growing polio epidemic.
July 1 – Rebuilt Milano Centrale railway station officially opens in Italy.
July 9 – Irish racing driver Kaye Don breaks the world water speed record at Lake Garda, Italy.
July 13 – Royal soldiers shoot and kill 22 people demonstrating against the Maharaja Hari Singh of the Indian princely state of Kashmir and Jammu. July 16 – Emperor Haile Selassie signs the first constitution of Ethiopia.
July 26 – The millennialist Bible Student movement adopts the name Jehovah's Witnesses at a meeting in Columbus, Ohio.
July 31 – The May Report in the United Kingdom recommends extensive cuts to government expenditure. This produces a political crisis as many members of the Labour Party (at this time in government) object to the proposals.
August
The 1931 China floods reach their peak in possibly the deadliest natural disaster yet recorded
August 9 – Referendum in Prussia for dissolving the Landtag ends with the "yes" side winning 37% of the vote, which is insufficient for calling the early elections. The elections are intended to remove the Social Democratic Party (SPD) government of Otto Braun, which is one of the strongest forces for democracy in Germany. Supporting the "yes" side were the NSDAP, the DNVP and the Communist Party (KPD) while supporting the "no" side were the SPD and Zentrum.
August 11 – Run on the British pound leads to political and economic crisis in Britain.
August 24 – The Labour Government of Ramsay MacDonald resigns in Britain, replaced by a National Government of people drawn from all parties, also under MacDonald.
September
September 18: The Mukden Incident: Incident Museum in Shenyang
September 5 – John Thomson, Scottish football player, dies as the result of an accident during a Celtic–Rangers match.
September 7 – Second Round Table Conference on the constitutional future of India opens in London. Mahatma Gandhi represents the Indian National Congress.
September 10 – The worst hurricane in British Honduras history kills an estimated 1,500.
September 15 – Invergordon Mutiny: Strikes are called in the British Royal Navy due to decreased pay.
September 16 – Hanging of resistance leader Omar Mukhtar in Italian Libya.
September 18
Japanese military stage the Mukden Incident as a pretext for the Japanese invasion of Manchuria.
Geli Raubal commits suicide in her uncle Adolf Hitler's apartment.
September 20 – With a gun literally pointed to his head the Chinese commander of Kirin province announces the annexation of that territory to Japan.
September 22 – The United Kingdom abandons the gold standard.
October
October – The Caltech Department of Physics faculty and graduate students meet with Albert Einstein as a guest.
October 4 – Dick Tracy, the comic strip detective character created by cartoonist Chester Gould, makes his debut appearance in the Detroit Mirror newspaper.
October 5 – American aviators Clyde Edward Pangborn and Hugh Herndon, Jr., complete the first non-stop flight across the Pacific Ocean, from Misawa, Japan, to East Wenatchee, Washington, in 41½ hours. October 11 – Rally in Bad Harzburg, Germany leads to the Harzburg Front being founded, uniting the NSDAP, the DNVP, the Stahlhelm and various other right-wing fractions.
October 17
American gangster Al Capone is sentenced to 11 years in prison for tax evasion in Chicago.
Leeds Bradford International Airport is opened as Leeds and Bradford Municipal Aerodrome in England.
October 24 – The George Washington Bridge across the Hudson River in the United States is dedicated; it opens to traffic the following day. At 3,500 feet (1,100 m), it nearly doubles the previous record for the longest main span in the world.
October 27 – United Kingdom general election results in the victory of the National Government and the defeat of Labour Party in the country's greatest ever electoral landslide.
November
November 7 – The Chinese Soviet Republic is proclaimed by Mao Zedong.
November 8 – Our Gang kid Darla Hood was born.
French police launch a large-scale raid against Corsican bandits.
The Panama Canal is closed for a couple of weeks due to damage caused by earthquakes.
November 21 – The infamous Red-and-White Party, given by Arthur Jeffress in Maud Allan’s Regent's Park townhouse in London, marks the end of the "Bright young things" subculture in Britain. November 25 – Heavy hydrogen, later named deuterium, is discovered by chemist Harold Clayton Urey.
Ali Fethi Okyar forms a new government in Turkey (third government).
Release of James Whale's film of Frankenstein in New York.
December
December 8 – Carl Friedrich Goerdeler is appointed Reich Price Commissioner in Germany to enforce the deflationary policies of the Brüning government.
December 10
Jane Addams became the first American woman to be awarded the Nobel Peace Prize.
Niceto Alcalá-Zamora is elected president of the Spanish Republic.
December 11 – The Parliament of the United Kingdom enacts the Statute of Westminster, which establishes a status of legislative equality between the self-governing dominions of the Commonwealth of Australia, the Dominion of Canada, the Irish Free State, Newfoundland, the Dominion of New Zealand and the Union of South Africa.
December 13 – Wakatsuki Reijirō resigns as Prime Minister of Japan.
December 26 – Phi Iota Alpha, the oldest existing Latino fraternity, is founded.
December 31 – Statute of Westminster creates the British Commonwealth of Nations.
January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics.
January 3 – Albert Einstein begins doing research at the California Institute of Technology, along with astronomer Edwin Hubble.
January 4 – German pilot Elly Beinhorn begins her flight to Africa.
January 6 – Thomas Edison submits his last patent application.
January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia.
January 25 – Mohandas Gandhi is again released from imprisonment in India.[citation needed]
January 27 – Pierre Laval forms a government in France.
January 30 – Release of the movie City Lights starring Charlie Chaplin.
February
February 3 – Hawke's Bay earthquake: Much of the New Zealand cities of Napier and Hastings are destroyed in an earthquake measuring 7.9 on the Richter scale killing 256 people.
February 4 – Soviet leader Joseph Stalin gives speech calling for rapid industrialization, arguing that only strong industrialized countries will win wars while "weak" nations are "beaten". Stalin states : "We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it, or they will crush us." Intensification of the First Five-Year Plan in the Soviet Union for industrialization and collectivization of agriculture.
February 10 – Official inauguration ceremonies for New Delhi as the capital of India begin. February 11 – National Socialist (NSDAP) and National Party (DNVP) members walk out of the German Reichstag in protest against changes in the parliament's protocol intended to limit heckling.
February 12 – Vatican Radio first broadcasts.
February 14 – The original film version of Dracula with Bela Lugosi is released in the United States.
February 16 – Pehr Evind Svinhufvud is elected president of Finland.
February 20 – California gets the go-ahead by the United States Congress to build the San Francisco–Oakland Bay Bridge.
February 21 – Peruvian revolutionaries hijack a Ford Trimotor aeroplane and demand that the pilot drop propaganda leaflets over Lima.
February 10: New Delhi becomes India's capital
February 21: Ford Trimotor hijacked
March
March 1 – The USS Arizona is placed back in full commission after a refit.
March 1 – Sir Oswald Mosley founds the New Party as a breakaway from the Labour Party in the United Kingdom.
March 3 – The Star-Spangled Banner is adopted as the United States' National anthem.
March 5 – The British viceroy of India and Mohandas Gandhi sign the Gandhi–Irwin Pact.
March 7 – The new House of Representatives opens in Helsinki, Finland.
March 11 – The Ready for Labour and Defence of the USSR programme, abbreviated as GTO, is introduced in the Soviet Union.
March 17 – Nevada legalizes gambling.
March 19 – Westminster St George's by-election in the U.K. results in the victory of the Conservative candidate Duff Cooper. The by-election has been treated virtually as a referendum on the leadership of the Conservative leader Stanley Baldwin, and Duff Cooper's victory ends the campaign by the press barons Lord Beaverbrook and Viscount Rothermere to oust Baldwin.
March 23 – Indian revolutionary leaders Bhagat Singh, Shivaram Rajguru and Sukhdev Thapar are hanged for conspiracy to murder in the British Raj.
March 25 – The Scottsboro Boys are arrested in Alabama and charged with rape.
March 27 – British writer Arnold Bennett dies of typhoid in London shortly after returning from a visit to Paris, where he drank local water to prove it was safe.
March 31 – An earthquake destroys Managua, Nicaragua, killing 2,000 people.
April
April 1 – The Second Encirclement Campaign against Jiangxi Soviet in China is launched by the Kuomintang government to destroy the Communist forces in Jiangxi province.
April 6 – The Portuguese government declares martial law in Madeira and in the Azores because of an attempted military takeover in Funchal.
April 9 – Argentinian anarchist Severino Digiovanni is executed.
April 12 – Municipal elections in Spain, which are treated as a virtual referendum on the monarchy, result in the triumph for the republican parties.
April 14 – The Second Spanish Republic is proclaimed in Madrid.
April 15 – The Castellammarese War ends with the assassination of Joe "The Boss" Masseria, briefly leaving Salvatore Maranzano as capo di tutti i capi ("boss of all bosses") and undisputed ruler of the American Mafia. Maranzano is himself assassinated less than 6 months later, leading to the establishment of the Five Families.
April 22 – Austria, Britain, Denmark, Germany, Italy, Sweden and the USA recognize the Spanish Republic.
May
May 1: Empire State Building is completed.
May 1 – Construction of the Empire State Building is completed in New York City.
May 4 – Kemal Atatürk is re-elected president of Turkey.
May 5 – İsmet İnönü forms new government in Turkey. (7th government)
May 11 – The Creditanstalt, Austria's largest bank, goes bankrupt, beginning the banking collapse in Central Europe that causes a worldwide financial meltdown.
May 13 – Paul Doumer is elected president of France.
May 15 – The Chinese Communists inflict a sharp defeat on the Kuomintang forces.
May 31 – The Second Encirclement Campaign against Jiangxi Soviet ends in defeat of the Kuomintang.
June
June 5 – German Chancellor Dr. Heinrich Brüning visits London, where he warns the British Prime Minister Ramsay MacDonald that the collapse of the Austrian banking system, caused by the bankruptcy of the Creditanstalt, has left the entire German banking system on the verge of collapse.
June 12 – English cricketer Charlie Parker equals J. T. Hearne's record for the earliest date to reach 100 wickets.
June 14 – The overloaded pleasure craft Saint-Philibert, carrying trippers home to Nantes from the Île de Noirmoutier, sinks at the mouth of the river Loire in France; over 450 drown.
June 19
In an attempt to stop the banking crisis in Central Europe from causing a worldwide financial meltdown, U.S. President Herbert Hoover issues the Hoover Moratorium.
The Geneva Convention (1929) relative to the treatment of prisoners of war enters into force.
June 23–July 1 – Wiley Post and Harold Gatty accomplish the first round-the-world flight in a single-engine plane, flying eastabout from Roosevelt Field, New York, in 8 days, 15 hours, 51 minutes.
July
July – John Haven Emerson of Cambridge, Massachusetts perfects his negative pressure ventilator ("iron lung") just in time for the growing polio epidemic.
July 1 – Rebuilt Milano Centrale railway station officially opens in Italy.
July 9 – Irish racing driver Kaye Don breaks the world water speed record at Lake Garda, Italy.
July 13 – Royal soldiers shoot and kill 22 people demonstrating against the Maharaja Hari Singh of the Indian princely state of Kashmir and Jammu. July 16 – Emperor Haile Selassie signs the first constitution of Ethiopia.
July 26 – The millennialist Bible Student movement adopts the name Jehovah's Witnesses at a meeting in Columbus, Ohio.
July 31 – The May Report in the United Kingdom recommends extensive cuts to government expenditure. This produces a political crisis as many members of the Labour Party (at this time in government) object to the proposals.
August
The 1931 China floods reach their peak in possibly the deadliest natural disaster yet recorded
August 9 – Referendum in Prussia for dissolving the Landtag ends with the "yes" side winning 37% of the vote, which is insufficient for calling the early elections. The elections are intended to remove the Social Democratic Party (SPD) government of Otto Braun, which is one of the strongest forces for democracy in Germany. Supporting the "yes" side were the NSDAP, the DNVP and the Communist Party (KPD) while supporting the "no" side were the SPD and Zentrum.
August 11 – Run on the British pound leads to political and economic crisis in Britain.
August 24 – The Labour Government of Ramsay MacDonald resigns in Britain, replaced by a National Government of people drawn from all parties, also under MacDonald.
September
September 18: The Mukden Incident: Incident Museum in Shenyang
September 5 – John Thomson, Scottish football player, dies as the result of an accident during a Celtic–Rangers match.
September 7 – Second Round Table Conference on the constitutional future of India opens in London. Mahatma Gandhi represents the Indian National Congress.
September 10 – The worst hurricane in British Honduras history kills an estimated 1,500.
September 15 – Invergordon Mutiny: Strikes are called in the British Royal Navy due to decreased pay.
September 16 – Hanging of resistance leader Omar Mukhtar in Italian Libya.
September 18
Japanese military stage the Mukden Incident as a pretext for the Japanese invasion of Manchuria.
Geli Raubal commits suicide in her uncle Adolf Hitler's apartment.
September 20 – With a gun literally pointed to his head the Chinese commander of Kirin province announces the annexation of that territory to Japan.
September 22 – The United Kingdom abandons the gold standard.
October
October – The Caltech Department of Physics faculty and graduate students meet with Albert Einstein as a guest.
October 4 – Dick Tracy, the comic strip detective character created by cartoonist Chester Gould, makes his debut appearance in the Detroit Mirror newspaper.
October 5 – American aviators Clyde Edward Pangborn and Hugh Herndon, Jr., complete the first non-stop flight across the Pacific Ocean, from Misawa, Japan, to East Wenatchee, Washington, in 41½ hours. October 11 – Rally in Bad Harzburg, Germany leads to the Harzburg Front being founded, uniting the NSDAP, the DNVP, the Stahlhelm and various other right-wing fractions.
October 17
American gangster Al Capone is sentenced to 11 years in prison for tax evasion in Chicago.
Leeds Bradford International Airport is opened as Leeds and Bradford Municipal Aerodrome in England.
October 24 – The George Washington Bridge across the Hudson River in the United States is dedicated; it opens to traffic the following day. At 3,500 feet (1,100 m), it nearly doubles the previous record for the longest main span in the world.
October 27 – United Kingdom general election results in the victory of the National Government and the defeat of Labour Party in the country's greatest ever electoral landslide.
November
November 7 – The Chinese Soviet Republic is proclaimed by Mao Zedong.
November 8 – Our Gang kid Darla Hood was born.
French police launch a large-scale raid against Corsican bandits.
The Panama Canal is closed for a couple of weeks due to damage caused by earthquakes.
November 21 – The infamous Red-and-White Party, given by Arthur Jeffress in Maud Allan’s Regent's Park townhouse in London, marks the end of the "Bright young things" subculture in Britain. November 25 – Heavy hydrogen, later named deuterium, is discovered by chemist Harold Clayton Urey.
Ali Fethi Okyar forms a new government in Turkey (third government).
Release of James Whale's film of Frankenstein in New York.
December
December 8 – Carl Friedrich Goerdeler is appointed Reich Price Commissioner in Germany to enforce the deflationary policies of the Brüning government.
December 10
Jane Addams became the first American woman to be awarded the Nobel Peace Prize.
Niceto Alcalá-Zamora is elected president of the Spanish Republic.
December 11 – The Parliament of the United Kingdom enacts the Statute of Westminster, which establishes a status of legislative equality between the self-governing dominions of the Commonwealth of Australia, the Dominion of Canada, the Irish Free State, Newfoundland, the Dominion of New Zealand and the Union of South Africa.
December 13 – Wakatsuki Reijirō resigns as Prime Minister of Japan.
December 26 – Phi Iota Alpha, the oldest existing Latino fraternity, is founded.
December 31 – Statute of Westminster creates the British Commonwealth of Nations.