Wetmore is an unincorporated community and a U.S. Post Office located in Custer County, Colorado, United States. The Wetmore Post Office has the ZIP Code 81253.A post office called Wetmore has been in operation since 1881. The community was named after William Wetmore, a first settler.Wetmore is located at 38°14′16″N 105°05′04″W / 38.23778°N 105.08444°W / 38.23778; -105.08444.