As of the census of 2010, there were 527 people, 216 households, and 152 families residing in the city. The population density was. There were 254 housing units at an average density of. The racial makeup of the city was 96.2% White, 0.6% Native American, 1.3% from other races, and 1.9% from two or more races. Hispanic or Latino of any race were 3.6% of the population. There were 216 households, of which 33.3% had children under the age of 18 living with them, 54.6% were married couples living together, 11.6% had a female householder with no husband present, 4.2% had a male householder with no wife present, and 29.6% were non-families. 27.3% of all households were made up of individuals, and 11.6% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.93. The median age in the city was 41.3 years. 27.5% of residents were under the age of 18; 6.8% were between the ages of 18 and 24; 21.8% were from 25 to 44; 27.2% were from 45 to 64; and 16.7% were 65 years of age or older. The gender makeup of the city was 52.2% male and 47.8% female.
2000 census
As of the census of 2000, there were 565 people, 230 households, and 158 families residing in the city. The population density was 564.0 people per square mile. There were 248 housing units at an average density of 247.6 per square mile. The racial makeup of the city was 98.58% White, 0.88% from other races, and 0.53% from two or more races. Hispanic or Latino of any race were 1.77% of the population. There were 230 households, out of which 33.9% had children under the age of 18 living with them, 57.0% were married couples living together, 8.7% had a female householder with no husband present, and 30.9% were non-families. 26.1% of all households were made up of individuals, and 13.0% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.92. In the city, the population was spread out, with 27.8% under the age of 18, 6.7% from 18 to 24, 27.3% from 25 to 44, 24.6% from 45 to 64, and 13.6% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 92.8 males. For every 100 females age 18 and over, there were 88.0 males. The median income for a household in the city was $38,269, and the median income for a family was $45,938. Males had a median income of $31,528 versus $24,250 for females. The per capita income for the city was $16,660. About 2.4% of families and 5.2% of the population were below the poverty line, including 4.4% of those under age 18 and 11.8% of those age 65 or over.
Services and attractions
Services provided by The City of Garwin include an ambulance service, a fire department, Green Mountain Garwin Junior/Senior High School, a public library, and a park. Located four miles northwest of town is Union Grove State Park. The park boasts a public beach, public fishing, picnic areas, campgrounds, and short hiking trails.
Education
The GMG Community School District serves the community. The district was established on July 1, 1992 by the merger of the Garwin and Green Mountain school districts. When Garwin and Green Mountain high schools combined to form the GMG High School in 1987, they adopted the nickname 'Wolverines'. Prior to the consolidation, Garwin athletes were known as 'Roughriders'. Student athletes can now compete in football, volleyball, cross country, boys' and girls' basketball, boys' and girls' track, boys' and girls' golf, baseball, softball, and share wrestling with East Marshall High School and swimming with Marshalltown High School. GMG High School has 1 IowaState High School Championship. The Wolverines claimed the 1987 Class AIowa State Football Championship in their first year as a combined school. GMG beat Schleswig 20–17 in overtime on a Robbie Sinclair touchdown run. GMG, coached by Fred Weick, finished the 1987 season 12–0, with two overtime wins coming in the first game of the season and the '87 championship game. GMG, and Garwin HS before it, also have a rich boys' basketball tradition. Garwin won many conference titles and made two runs to the Iowa State Basketball Tournament. Garwin first made the 1978 Class 1A State Tournament, losing to Lake View-Auburn 54–44. They also made it to the 1983 Class 1A Championship Game, losing to Palmer 61–55. Garwin/GMG was long coached by Gary Peterson, who over his 33 years as head coach, amassed a record of 478 wins and 216 losses, which ranks him 34th all time in Iowa boys' basketball history. GMG had a lot of success in the mid-1990s winning back-to-back-to-back NICL West titles in boys' basketball and a district football title in 1999. The 2007-08 girls' basketball team, under coach Jay Freese, posted a record of 20-3 and made the program's first ever regional final. In the 2010 football season, the team became the first to ever go 0-10 and lose each game by at least two touchdowns. The boys' basketball team also struggled, going 3-17.
