- Sep 1 Timberlake Westenbaker's "Our Country's Good" premieres in London
- Sep 2 Amnesty International's Human Rights Now! tour begins in Wembley
- Sep 3 Estimated by this date 50,000 Kurdish civilians and soldiers killed by Iraq, many using chemical weapons, in aftermath of Iran-Iraq War
- Sep 6 Crippled soviet Soyuz TM-5 lands safely with 2 cosmonauts aboard
- Sep 6 Thomas Gregory (11) swims English Channel
- Sep 6 USSR performs underground nuclear test
- Sep 7 Security & Exchange Commission accuses Drexel of violating security laws
- Sep 10 -18] Hurricane Gilbert, kills 300 in Jamaica, Texas & Yucatan
- Sep 11 1/3 of population argues for Estonia autonomy
- Sep 12 Gilbert, strongest hurricane ever (160 mph), devastates Jamaica
- Sep 13 9 hard/software manufacturers announce EISA computer bus in NY
- Sep 13 Gilbert is strongest (26.13 barometer) hurricane in Western Hemisphere
- Sep 14 USSR performs nuclear test at Eastern Kazakh/Semipalitinsk USSR
- Sep 15 Museum of Moving Image in London opens
- Sep 17 Jeff Reardon becomes 1st to record 40 or more saves in both AL & NL
- Sep 17 13th Toronto International Film Festival: "Women on the Verge of a Nervous Breakdown" directed by Pedro Almodovar wins the People's Choice Award
- Sep 18 Coup in Haiti: General Prosper Avril takes control, Henri Namphy flees
- Sep 18 Burma suspends its constitution
- Sep 19 Israel launches 1st satellite, for secret military reconnaissance
- Sep 20 Wade Boggs is 1st player to get 200 hits for 6 consecutive seasons
- Sep 22 Canada begins production of a $5 silver Maple Leaf bullion coin
- Sep 23 Fiji's new constitution is proposed
- Sep 23 Premiere of director Paul Schrader's crime biopic "Patty Hearst"
- Sep 24 Barbara C Harris of Mass, elected 1st woman Episcopal bishop
- Sep 24 Canada's Ben Johnson runs drug-assisted 100m in 9.79 sec
- Sep 24 Dave Stieb has no-hitter broken up with 2 outs in the 9th
Beatification
Sep 25 Pope John Paul II beatifies Friar Junípero Serra (founder of 1st Californian missions)
Junípero Serra
John Paul II
- Sep 26 Canada's Ben Johnson stripped of his 100-m gold failing drug test
- Sep 26 NYC's Rockefeller Center declared a national landmark
- Sep 26 Polish communist party picks propaganda chief Rakowski as new PM
- Sep 26 US space shuttle STS-26 launched
- Sep 27 Grand jury evidence shows Tawana Brawley fabricated rape story
- Sep 27 Senate votes for major federal tax code changes
Event of Interest
Sep 27 The National League for Democracy, led by Aung San Suu Kyi is founded in Burma (Myanmar)
Aung San Suu Kyi
- Sep 27 Canadian Finn class sailor Lawrence Lemieux abandons race 5 to assist injured competitor after being in 2nd place; selfless act is awarded with the Pierre de Coubertin medal
- Sep 28 Bronx Museum for Arts opens
- Sep 28 LA Dodger Orel Herschiser breaks former Dodger Don Drysdale's record by pitching 59 consecutive scoreless innings
- Sep 29 26th Space Shuttle mission, Discovery 7 launched
- Sep 29 China performs nuclear test at Lop Nor, PRC
- Sep 29 UN peacekeeping forces win Nobel Peace prize
- Sep 29 Union Station reopens in Washington, D.C.
- Sep 30 Andrei Andreyevich Gromyko retires as Soviet Foreign Minister
- Sep 30 Dave Stieb loses 2nd consecutive no hitter bid with 2 outs in 9th
- Sep 30 IBM announces shipment of 3 millionth PS/2 personal computer