the west by the Chattahoochee River, which serves as the Fulton County border, and across which is the city of Johns Creek. According to the United States Census Bureau, Suwanee has a total area of , of which is land and , or 0.70%, is water. There are multiple areas with Suwanee postal addresses that are in unincorporated Gwinnett County and in unincorporated Forsyth County; those areas are not in the Suwanee corporate limits. Climate Suwanee has a humid subtropical climate (Köppen climate classification Cfa), with mild winters and hot, humid summers. Demographics 2020 census As of the 2020 United States census, there were 20,786 people, 7,012 households, and 5,235 families residing in the city. 2010 census As of 2010, Suwanee had a population of 15,355. The racial and ethnic composition of the population was 67.4% white, 10.8% black or African American, 0.1% Native American, 18.0% Asian, 0.1% Pacific Islander, 1.3% reporting some other race, and 2.3% reporting two or more races. 6.75% of the population was Hispanic or Latino of any race. 2000 census As of the census of 2000, there were 8,725 people, 2,947 households, and 2,375 families residing in the city. The population density was . There were 3,144 housing units at an average density of . The racial makeup of the city was 84.49% White, 6.38% African American, 0.13% Native American, 6.84% Asian, 0.01% Pacific Islander, 0.72% from other races, and 1.42% from two or more races. Hispanic or Latino of any race were 3.16% of the population. There were 2,947 households, out of which 46.8% had children under the age of 18 living with them, 71.8% were married couples living together, 6.0% had a female householder with no husband present, and 19.4% were non-families. 14.5% of all households were made up of individuals, and 1.9% had someone living alone who was 65 years of age or older. The average household size was 2.89 and the average family size was 3.23. In the city, the population was spread out, with 29.5% under the age of 18, 6.1% from 18 to 24, 39.3% from 25 to 44, 20.7% from 45 to 64, and 4.3% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 102.2 males. For every 100 females age 18 and over, there were 101.8 males. The median income for a household in the city