The site for the CCAT Observatory was first proposed in 2006 with a final selection in 2008. Since 2006, extensive meteorological measurements have been performed to determine and characterize its submillimeter observing characteristics.
The exact location of the site is 5612 meters altitude about 200 meter ENE of and 50 meters below the summit of Cerro Chajnantor. The air temperature, pressure, humidity, and wind is recorded by a weather station every 15 minutes. In addition, at approximate 15 minute intervals, a tipper measures the atmospheric transparency at the nominal submillimeter wavelengths of 350 μm and 200 μm.