Greenwich is an unincorporated community in Sedgwick County, Kansas, United States. Greenwich is 9.5 miles northeast of downtown Wichita. Greenwich has a post office with ZIP code 67055.Greenwich had its start by the building of the St. Louis, Fort Scott & Wichita Railroad through that territory.The first post office in Greenwich was established in September 1874.The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Greenwich has a humid subtropical climate, abbreviated "Cfa" on climate maps.