Nagasaki was bombed on August 9, 1945, shortly before Japan’s surrender announcement.
The United States dropped the atomic bomb called Fat Man on Nagasaki three days after the bombing of Hiroshima. The bomb was carried by the B-29 bomber Bockscar and detonated over the city on August 9. A planned primary target, Kokura, was obscured by cloud and smoke, so the aircraft proceeded to its secondary target, Nagasaki.
The bombing occurred on the same day that Soviet forces began their invasion of Japanese-held Manchuria. Japanese leaders were therefore confronting both the use of atomic weapons and the collapse of their diplomatic hope that the Soviet Union might mediate.
Hiroshima and Nagasaki are often remembered together, but they were different cities targeted on different dates with different bombs. Emperor Hirohito announced Japan’s acceptance of the Allied terms on August 15, and the formal surrender was signed on September 2.