Nuclear Testing Chronology
Since the first nuclear test explosion on July 16, 1945, at least eight nations have detonated 2,056 nuclear test explosions at dozens of test sites, including Lop Nor in China, the atolls of the Pacific, Nevada, Algeria where France conducted its first nuclear device, western Australia where the U.K. exploded nuclear weapons, the South Atlantic, Semipalatinsk in Kazakhstan, across Russia, and elsewhere.
India's three simultaneous nuclear explosions on May 11 are counted as only one nuclear test, as are the two explosions on May 13. Likewise, Pakistan's five simultaneous explosions on May 28 are counted as a single test. North Korea's tests in April and May 2010 were too low to be considered actual nuclear tests, and are not counted here.
First nuclear test: July 16, 1945
Most recent nuclear test: Sept. 23, 1992
Total tests: 1,030 (815 underground)
The United States has conducted more tests than the rest of the world, and was the first and only country to use a nuclear weapon in wartime. The U.S. has signed the Comprehensive Test Ban Treaty, but it has not yet been ratified by the Senate.
First nuclear test: Aug. 29, 1949
Most recent nuclear test: Oct. 24, 1990
Total tests: 715 (496 underground)
Russia was the second nation in the world to conduct nuclear tests.
First nuclear test: Oct. 3, 1952
Most recent nuclear test: Nov. 26, 1991
Total tests: 45 (24 underground)
Britain tested its first nuclear weapon on Monte Bello Islands, Australia. Atmospheric tests were carried out there until 1956. Britain has ratified the Comprehensive Test Ban Treaty.
First nuclear test: Feb. 13, 1960
Most recent nuclear test: Jan. 27, 1996
Total tests: 210 (160 underground)
France conducted six controversial tests as recently as 1995-1996.
First nuclear test: Oct. 16, 1964
Most recent nuclear test: July 29, 1996
Total tests: 43 (22 underground)
China is widely thought to be helping Pakistan with its nuclear efforts.
First nuclear test: May 18, 1974
Most recent nuclear test: May 13, 1998
Total tests: 7
In 1966, India declared it could produce nuclear weapons within 18 months. Eight years later, India tested a device of up to 15 kilotons and called the test a "peaceful nuclear explosion." In May 1998, India stunned the world when it conducted two underground nuclear tests in Pokharan, Rajasthan, and declared itself a nuclear state.
First nuclear test: May 28, 1998
Most recent nuclear test: May 30, 1998
Total tests: 6
In 1972, following its third war with India, Pakistan secretly decided to start a nuclear weapons program to match India's developing capability. Pakistan responded to India's nuclear tests in 1998 by announcing it exploded an underground device in the Chagai region (close to its border with Iran).
First nuclear test: Oct. 9, 2006
Most recent nuclear test: Sept. 3, 2017.
Total tests: 3
On October 9, 2006 North Korea announced they had conducted a nuclear test. It is assumed this test was actually a fizzle. A second test was conducted on May 25, 2009. This test appeared to be successful. A third test was conducted on February 12, 2013.
Sources: National Resources Defense Council and Arms Control Association