Blue, Arizona  Blue (originally, Whittum) is an unincorporated community in Greenlee County, Arizona, United States. It lies (33.6100552, -109.1067396), at an elevation of 5,758 feet (1,755 m). The community was originally named for Nat Whittum, an original settler who was killed at the site in 1891. A post office was established at Whittum in 1894; however, its name was changed to Blue in 1898, because everyone knew where the Blue River was but Whittum was not known. Blue has a ZIP Code of 85922; in 2000, the population of the 85922 ZCTA was 36. In addition to its post office, Blue also contains a public library, and a public school serving all grade levels. This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F. According to the Köppen Climate Classification system, Blue has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps.