The nuclear weapons age began on 16 July 1945 when the U.S. exploded the first nuclear bomb, codenamed 'Trinity' at Alamogordo, New Mexico. The Soviet Union was the next country to explode a bomb, with a test on 29 August 1949. Other countries followed: Britain's first test was on 3 October 1952; France's on 3 December 1960; China's on 16 October 1964 and; India's on 18 May 1974.
The "thermonuclear age" began on 1 November 1952 when the U.S. exploded the first thermonuclear bomb at Eniwetok atoll in the Pacific. Codenamed 'Mike', this bomb was 500 times more powerful than the 'Trinity' test and had an estimated yield of 10.4 megatons. As for the other thermonuclear states: the Soviet Union tested its first thermonuclear bomb on 22 November 1955; China on 17 June 1967; Britain on 8 November 1957 and; France on 24 August 1968.
The U.S. has carried out 1,030 nuclear weapons tests (the last and final test on 23 September 1993). The Soviet Union: 715 tests (the last on 25 October 1990 -- Russia has not exploded any nuclear weapons). France: 210 tests (the last and final test on 27 January 1996). Britain: 45 tests (the last and final on 26 November 1991). China: 43 tests (with some four more tests reportedly planned for 1996-1997).
The average pace of nuclear weapons testing is remarkable: Since 16 July 1945 there have been 2,044 tests worldwide, the equivalent of one test occurring somewhere in the world every nine days for the last fifty years.
The U.S. has conducted the equivalent of one nuclear weapons test every 17 days since its first test; the Soviet Union has tested on average every 23 days; France every 63 days; Britain every 349 days and; China every 222 days. India has conducted only one test so far.
Nuclear weapon test explosions have been carried out in all environments: above ground, underground, and underwater. They have occurred on top of towers, onboard barges, suspended from balloons, on the earth's surface, underwater to depths of 2,000 feet, underground to depths of more than 8,000 feet, and in horizontal tunnels. Test bombs also have been dropped by aircraft and fired by rockets up to 200 miles into the atmosphere.
Nuclear weapons tests have been carried out all over the world. In the Pacific at: Bikini Atoll (U.S.); Christmas Island (U.S./U.K.); Eniwetok Atoll (U.S.); Fangataufa Atoll (Fr); Johnston Atoll (U.S.); Malden Island (U.K.) and; Mororua Atoll (Fr). Also, in Australia, Monte Bello Island, at Emu Fields, and Maralinga (U.K. tests).
In the U.S.: Nevada (several sites; but the Nevada Test Site is the only currently open U.S. test site); Alamogordo, New Mexico; Carlsbad, New Mexico; Hattiesberg, Mississippi; Grand Valley, Colorado; Rifle, Colorado; Farmington, New Mexico; Hot Creek Valley, Central Nevada; Fallon, Nevada and; Amchitka, Alaska.
In the Soviet Union: the Arctic Islands of Novaya Zemlya (the only currently open Russian test site); Semipalatinsk in eastern Kazakhstan; near Azgir and Astrakhan in western Kazakhstan; near Orenburg between the Volga river and the Ural mountains; in the Ukraine; in Uzbekistan, and in Turkmenistan.
In Algeria: near Reggane, and in the Hoggar Massif at In Ecker (French tests). In China: at the Lop Nor Test Site in Xingjiang Province (the currently open Chinese test site). In India: at the Pokhran test site. Also, in the South Atlantic, (U.S.; rocket launched tests).
Of the 2,044 nuclear weapons tests worldwide, there have been 711 in the atmosphere or underwater: 215 by the U.S., 207 by the Soviet Union, 21 by Britain, 45 by France and, 23 by China.
The last atmospheric nuclear weapons test occurred on 16 October 1980 in China. The first was on 16 July 1945 in the U.S.
It is estimated that the total yield of all the atmospheric nuclear weapons tests conducted is 438 megatons. That's equivalent to 29,200 Hiroshima size bombs. In the 36 years between 1945 and 1980 when atmospheric testing was being conducted this would have been equivalent to exploding a Hiroshima size bomb in the atmosphere every 11 hours.