Hiroshima Peace Memorial Day

What Is Hiroshima Peace Memorial Day?

Every August 6th is "Hiroshima Peace Memorial Day" (広島平和記念日, Hiroshima Heiwa Kinenbi) — also known as the "Atomic Bomb Anniversary" (原爆忌, Genbaku Ki). At 8:15 a.m. on August 6, 1945, the United States B-29 bomber Enola Gay dropped the first atomic bomb ever used in warfare — "Little Boy," a uranium gun-type device — on the city of Hiroshima. The explosion immediately killed an estimated 70,000–80,000 people; by the end of 1945, the death toll had risen to approximately 140,000 as victims of radiation, burns, and injuries succumbed. Hiroshima was the first city in history to experience nuclear attack.

The Moment of Detonation

The atomic bomb detonated at approximately 600 meters above the city — the height calculated to maximize the blast radius. The fireball reached temperatures of several million degrees Celsius; the shockwave flattened buildings across a 2-kilometer radius from ground zero; and intense radiation and a firestorm swept through the city in the aftermath. The hypocenter — directly below the explosion — was near the Shima Hospital in the commercial center of Hiroshima. The Genbaku Dome (原爆ドーム, the ruins of the Hiroshima Prefectural Industrial Promotion Hall), which survived partially standing, became the iconic memorial to the bomb's destruction.

The Hibakusha

Survivors of the atomic bombings are known as "hibakusha" (被爆者, literally "explosion-affected people"). Many survived the immediate blast only to suffer long-term effects of radiation exposure — increased rates of cancer, particularly leukemia, chronic health conditions, and social discrimination (some employers and potential marriage partners avoided hibakusha out of unfounded fears of contamination). The hibakusha's testimony has been essential to communicating the human reality of nuclear weapons to successive generations.

The Peace Memorial Ceremony

Every August 6th at 8:15 a.m., the Hiroshima Peace Memorial Ceremony is held at the Peace Memorial Park, centered on the cenotaph bearing the inscription: "Let all the souls here rest in peace, for we shall not repeat the evil." A minute of silence is observed at the exact moment of detonation. Representatives of cities around the world, heads of state, and survivors gather to reaffirm the commitment to a world free of nuclear weapons. The Peace Flame in the park has burned continuously since 1964 and will be extinguished only when all nuclear weapons are abolished.

Fun Facts

• Paper cranes: Sadako Sasaki, a young girl who survived the bomb but developed leukemia, folded paper cranes (鶴, tsuru) in the hope that reaching 1,000 would grant her wish to recover. She died in 1955 at age 12; her story made the paper crane the global symbol of peace and Hiroshima's memory.
• The Genbaku Dome: The Atomic Bomb Dome is a UNESCO World Heritage Site — designated in 1996 as a monument to peace and a reminder of the consequences of nuclear war.