- Jan 1 Earl Claus von Stauffenberg promoted to 2nd lieutenant
- Jan 1 Jurgens & Van den Berg merge with Lever Brothers to form Unilever
- Jan 1 16th Rose Bowl: Southern California beats Pittsburgh, 47-11
Historic Event
Jan 5 Mao Zedong writes "A Single Spark Can Start a Prairie Fire"
Meeting of Interest
Jan 5 Bonnie Parker meets Clyde Barrow for the first time at Clarence Clay's house
- Jan 6 1st diesel engine automobile trip (in a Packard sedan) completed
Historic Event
Jan 9 Albert Kahn Associates architectural firm become consulting architects for all industrial construction in the Soviet Union
- Jan 10 Commencement of NZ's 1st Test, v England in Christchurch, New Zealand
- Jan 10 Maurice Allom takes Test hat-trick England v NZ Christchurch
- Jan 10 Mordovian Autonomous Region in RSFSR constituted
- Jan 13 "Mickey Mouse" comic strip 1st appears
- Jan 15 Brilliant West Indian cricket batsman George Headley scores 157 of 176 on debut on the 4th day of the drawn 1st Test against England in Bridgetown, Barbados
- Jan 18 -27°F (-33°C), Watts, Oklahoma (state record)
Music Premiere
Jan 18 Dmitri Shostakovich's satirical opera "The Nose" premieres in Leningrad
- Jan 20 1st radio broadcast of "Lone Ranger" (WXYZ-Detroit)
- Jan 21 Boston Bruins become first team in NHL history to score 100 goals in a season, in a 5-1 win over Chicago at Boston Garden; Cooney Weiland scores Bruins' 100th goal in their 26th game of the year
- Jan 22 -35°F (-37°C), Mount Carroll, Illinois (state record)
- Jan 23 Clyde Tombaugh photographs dwarf planet Pluto
- Jan 23 George Washington Birthplace National Monument, Virginia established
- Jan 23 WIS-AM (now WOMG) in Columbia SC begins radio transmissions
- Jan 24 J E Mills scores 117 on Test Cricket debut, NZ v England, Wellington
- Jan 24 Stewie Dempster scores New Zealand's 1st Test century
- Jan 25 Australian Championships Women's Tennis, Melbourne: Daphne Akhurst Cozens wins 3rd straight Australian singles title; beats Sylvia Lance Harper 10-8, 2-6, 7-5
- Jan 25 Australian Championships Men's Tennis: Edgar Moon wins his first and only Grand Slam singles title; beats fellow Australian Harry Hopman 6-3, 6-1, 6-3
- Jan 26 Cleveland's Terminal Tower opens (52 stories)
- Jan 30 Vladimir Mayakovsky's drama "Banya - (The Bathhouse)" premieres in Leningrad
- Jan 30 Russia launches their 1st radiosonde - a battery-powered telemetry instrument carried into the atmosphere to measure various parameters and transmit them by radio to a ground receiver- from Pavlovsk, USSR.
- Jan 31 1st US glider flight from a dirigible, Lakehurst, New Jersey