Mercury is a closed village in Nye County, Nevada, United States, north of U.S. Route 95 at a point northwest of Las Vegas. It is situated within the Nevada National Security Site and was constructed by the Atomic Energy Commission to house and service the staff of the test site. The specific site was known as Jackass Flats and nearby Nevada Test Site 400. Today, the site is governed by the United States Department of Energy. As part of the test site, the village is not accessible to the general public. It was named after the mercury mines which flourished in its general vicinity a century before the village itself was established. The current population is unknown. Climate According to the Köppen Climate Classification system, Mercury has a cold desert climate, abbreviated "BWk" on climate maps. The hottest temperature recorded in Mercury was on July 11, 2021, while the coldest temperature recorded was on December 22, 1990. History The village started in 1950 at the beginning of operations of the Nevada Test Site as Base Camp Mercury, a military-style encampment built to provide basic facilities for personnel involved. As the scope of the testing program expanded, so did the number of personnel required to fulfill the site's mission, and beginning in 1951 a $6.7 million construction project was undertaken to provide adequate individual housing, office, and service structures with a civilian village-like design. With the acquisition of a full-service post office in the mid-1950s, Base Camp Mercury was formally renamed Mercury, Nevada. In 1957, the US Navy launched nine atmospheric sounding rockets to measure nuclear radiation and other atmospheric data, using Mercury as a staging area. The Naval Radiological Defense Laboratory conducted its first test flight in 1956. This test rocket lifted to an altitude of . In the early 1960s the village population grew to over 10,000, and further construction work was undertaken to upgrade the permanence of the village. A school was established, and numerous recreational and shopping facilities were added, including a movie theater, bowling alley, recreation hall, swimming pool, and hobby center, as well as a full-care health clinic, library, lodging (the Atomic Motel being the most prominent example), a non-denominational chapel with a cadre of chaplains, a service station with a garage, and a bus station. In 1962, the Desert Rock Airport was added for the visit from President John F. Kennedy on December 8.