List of nuclear weapons tests of the United States

All testing was voluntarily terminated in 1958, leading to Partial Test Ban Treaty in 1963

See also: Nuclear arms race

See also: Nuclear weapons of the United States

As part of the nuclear arms race, the United States conducted around 1,054 nuclear tests (by official count) between 1945 and 1992, including 216 atmospheric, underwater, and space tests. Most of the tests took place at the Nevada Test Site and the Pacific Proving Grounds in the Marshall Islands and off Kiribati Island in the Pacific, plus three in the Atlantic Ocean. Ten other tests took place at various locations in the United States, including Alaska, Nevada other than the NNSS/NTS, Colorado, Mississippi, and New Mexico.

1945–1958

Year	Series	No. shots	Total yields	Location(s)	Image	Notes
1945	Trinity	1	20 kt	Alamogordo, New Mexico		First ever nuclear explosion.
1946	Crossroads	2	46 kt	Pacific Proving Grounds		First postwar test series. First underwater nuclear explosion.
1948	Sandstone	3	104 kt	Pacific Proving Grounds		The first use of "levitated" cores. Developed the Mark IV warhead.
1951	Ranger	5	40 kt	Nevada Test Site		First tests at the Nevada Test Site.
1951	Greenhouse	4	398.5 kt	Pacific Proving Grounds		"George" shot was physics experiment relating to the hydrogen bomb; "Item" shot was first boosted fission weapon.
1951	Buster-Jangle	7	71.9 kt	Nevada Test Site		Many shots done in conjunction with troop exercises on ground.
1952	Tumbler-Snapper	7	104 kt	Nevada Test Site		Operation "Snapper" tested a number of new devices, and also explored the "rope trick effect".
1952	Ivy	2	10.9 Mt	Pacific Proving Grounds		"Mike" shot was first hydrogen bomb; "King" shot was largest pure-fission bomb (500 kt).
1953	Upshot-Knothole	11	252.4 kt	Nevada Test Site		Grable shot used a 280mm M65 Atomic cannon.
1954	Castle	6	48.2 Mt	Pacific Proving Grounds		Deployable thermonuclears. "Bravo" was over twice as large as expected (most powerful ever by U.S.) and spread fallout over a wide area. Hydrogen bombs that used cryogenic fuel were obsolete.
1955	Teapot	14	167.8 kt	Nevada Test Site		First successful designs by Lawrence Livermore National Laboratory (after two years of trying).
1955	Wigwam	1	30 kt	Pacific Ocean		A single shot, 2000 ft underwater, to determine the vulnerability of submarines to nuclear explosions.
1955-56	Project 56	4	.01 to .1 kt	Nevada Test Site		Four 'one-point' safety tests, to ensure the safety of deployed designs.
1956	Redwing	17	20.82 Mt	Pacific Proving Grounds		All thermonuclear weapons designs tests, including first "three stage" weapon test.
1957	Project 57	1	0 t	Nellis Air Force Range		One 'one-point' safety test, to ensure the safety of deployed designs.
1957	Plumbbob	29	343.74 kt	Nevada Test Site		One of the most controversial test series, release more radiation to continental U.S. than any series. Close proximity of troop exercises to shot "Smoky" produced significantly increased levels of leukemia among exposed soldiers.[citation needed]
1957–58	Project 58, Project 58A	4	0.5 kt	Nevada Test Site		Four 'one-point' safety tests, to ensure the safety of deployed designs.
1958	Chariot	Cancelled		Cape Thompson, Alaska		Had planned to create an artificial harbor in Alaska as part of Operation Plowshare using thermonuclear explosions. Was eventually canceled amid controversy.
1958	Operation Hardtack I	35	35.6 Mt	Pacific Proving Grounds		First live nuclear bomb launched by a missile (U.S. Army's PGM-11 Redstone)
1958	Argus	3	5.1 kt	South Atlantic Ocean		Clandestine high-altitude test series carried out 1,110 miles southwest of South Africa to test whether nuclear explosions could create artificial Van Allen belts in near space.
1958	Operation Hardtack II	37	45.8 kt	Nevada Test Site

Testing Moratorium of 1959–1960

A voluntary moratorium terminates all nuclear testing for the US along with the Soviet Union and the United Kingdom. The moratorium is broken by France, becoming the fourth nuclear state with its test, "Gerboise Bleue", on February 13, 1960. The Soviet Union responds by breaking the moratorium on September 1 by resuming testing (including the 50 Mt "Tsar Bomba" device on October 30, 1961) and the US joins in breaking the moritorium by resuming weapons testing on 15 September 1961.

1961–1963

Year	Series	No. shots	Total yields	Location(s)	Image	Notes
1961–62	Nougat	32		Nevada Test Site, Carlsbad, New Mexico		First all-underground test series. Included Operation Plowshare shot "Gnome" in Carlsbad, New Mexico, which was detonated in an underground salt dome.
1962–63	Dominic	36	38.1 Mt	Christmas Island, Johnston Island, Central Pacific Ocean		"Frigate Bird" was the only operational test of a missile "mated" with a live warhead. Series also included three high-altitude tests known as Operation Fishbowl.
1962–63	Storax	48		Nevada Test Site		Included the "Sedan" test, a cratering experiment as part of Operation Plowshare.
1962	Sunbeam	4	2.19 kt	Nevada Test Site		Test of small tactical warheads, including the man-portable "Davy Crockett". Last atmospheric test series.
1963	Roller Coaster	4	0	Nellis Air Force Range, Nevada		Storage-transportation safety experiment, measured plutonium dispersal risk.

After the signing of the Partial Test Ban Treaty in 1963, all U.S. nuclear testing became underground testing.

1964–1992

Year	Series	No. shots	Total yields	Location(s)	Notes
1964–65	Niblick	41		Nevada Test Site, Fallon, Nevada
1964–65	Whetstone	48		Nevada Test Site, Hattiesburg, Mississippi
1965–66	Flintlock	48		Nevada Test Site, Amchitka, Alaska
1966–67	Latchkey	38		Nevada Test Site, Hattiesburg, Mississippi
1967–68	Crosstie	48		Nevada Test Site, Farmington, New Mexico, Hot Creek Valley, Nevada	Included "Gasbuggy" Plowshare shot near Farmington, New Mexico and "Faultless" shot in Nevada's Hot Creek valley.
1968–69	Bowline	48		Nevada Test Site
1969	Mandrel	53		Nevada Test Site; Grand Valley, Colorado; Amchitka, Alaska	Included "Rulison" Plowshare shot near Grand Valley, Colorado, and 1.2 Mt shot "Milrow" in Alaska.
1970	Emery	16		Nevada Test Site
1971–72	Grommet	34		Nevada Test Site, Amchitka, Alaska	Included largest US underground detonation, the > 5 Mt shot "Cannikin" (for the Spartan Missile warhead) in Alaska.
1972–73	Toggle	28		Nevada Test Site, Rifle, Colorado	Included Plowshare "Rio Blanco" test for gas stimulation
1973–74	Arbor	19		Nevada Test Site
1974–75	Bedrock	27		Nevada Test Site
1975–76	Anvil	21		Nevada Test Site
1976–77	Fulcrum	21		Nevada Test Site	All "weapons related" tests.
1977–78	Cresset	23		Nevada Test Site
1978–79	Quicksilver	18		Nevada Test Site
1979–80	Tinderbox	15		Nevada Test Site
1980–81	Guardian	16		Nevada Test Site
1981–82	Praetorian	22		Nevada Test Site
1982–83	Phalanx	19		Nevada Test Site
1983–84	Fusileer	17		Nevada Test Site
1984–85	Grenadier	17		Nevada Test Site
1985–86	Charioteer	18		Nevada Test Site	Mighty Oak test using the Mk-21 RV warhead. was conducted on April 10, 1986. Containment failed and later radiation was released. Secondary sources put this venting into at 36,000 curies, which is 2000 times greater than the 3 Mile Island incident. Sources: Dr. Rosalie Bertell, Dr. Bonnie Eberhardt, journalist Paul Van Dam.
1986–87	Musketeer	15		Nevada Test Site
1987–88	Touchstone	14		Nevada Test Site
1988–89	Cornerstone	12		Nevada Test Site
1989–90	Aqueduct	11		Nevada Test Site
1990–91	Sculpin	8		Nevada Test Site
1991–92	Julin	8	<460kt	Nevada Test Site	Last nuclear test series. Last shot was "Divider" (September 23, 1992). Exact yields not released.

A number of shots whose goals were to assess the non-military use of nuclear weapons were known as Operation Plowshare, and done during many different test series.

The United States has not conducted any tests since 1992, though they have conducted a number of sub-critical tests (which do not involve a chain reaction).

The United States has signed, but not ratified the Comprehensive Nuclear Test Ban Treaty.