• September 2 – Ten men from the 612th Bomb Squadron stationed at Great Falls were killed in a B-17 crash five miles east of Ft. Benton during a training exercise.
• September 3 – British forces invaded southern Italy. Thousands viewed the pet and doll parade in Great Falls.
• September 8 – The surrender of Italy was announced.
• September 9 – The U.S. Fifth Army landed at Salerno, Italy and the Third War Bond drive began.
• September 10 – Convicted murderer Philip Coleman was executed at the Missoula County Jail. Two aviation instructors and two students were killed in a collision of their planes near the Missoula airport.
• September 12 – Australian troops and the 163rd Infantry captured Salamaua, New Guinea. The Italian dictator Mussolini was freed from captivity by Nazi commandos.
• September 13 – Gen. Chiang Kai-shek was declared president of China.
• September 16 – Australian troops on New Guinea captured Lae.
• September 24 – A 7th Ferrying Group pilot was killed in an air crash at Great Falls. The Germans evacuated Smolensk. A welder started a fire that resulted in $60,000 damages to the American Crystal Sugar Co. in Missoula.
• September 25 – Duck season opened.
• September 26 – O.F. Goddard, former chief justice of the Montana Supreme Court, died in Billings at age 90.
• September 27 – Residents of Naples revolted against German occupiers upon the approach of British troops.
• September 30 – Silk recycling was halted because it had been so successful.
Montana History Calendar 1930s
October 1943 (coming soon)