The Mason City Micropolitan Statistical Area includes all of Cerro Gordo and Worth counties.
The city is notable as the place from which Buddy Holly, Ritchie Valens and the Big Bopper took off on the night of February 3, 1959 after a concert at the Surf Ballroom in nearby Clear Lake, Iowa, only to crash in a historic event later referred to as the Day the Music Died.
As of the census of 2000, there were 29,172 people, 12,368 households, and 7,507 families residing in the city. The population density was 1,131.3 people per square mile (436.7/km²). There were 13,029 housing units at an average density of 505.3/sq mi (195.1/km²). The racial makeup of the city was 95.40% White, 1.17% African American, 0.18% Native American, 0.77% Asian, 0.01% Pacific Islander, 1.07% from other races, and 1.40% from two or more races. Hispanic or Latino of any race were 3.45% of the population.
There were 12,368 households out of which 28.4% had children under the age of 18 living with them, 47.4% were married couples living together, 10.3% had a female householder with no husband present, and 39.3% were non-families. 33.5% of all households were made up of individuals and 14.6% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.90.
In the city the population was spread out with 23.6% under the age of 18, 10.2% from 18 to 24, 26.7% from 25 to 44, 21.7% from 45 to 64, and 17.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 90.0 males. For every 100 females age 18 and over, there were 85.8 males.
The median income for a household in the city was $33,852, and the median income for a family was $45,160. Males had a median income of $32,451 versus $21,756 for females. The per capita income for the city was $18,899. About 7.2% of families and 10.0% of the population were below the poverty line, including 10.9% of those under age 18 and 10.1% of those age 65 or over.
The city is served by Iowa Highway 122, and U.S. Highway 65. U.S. Highway 18 now bypasses the city to the south. Interstate 35 (eight miles to the west) serves the city as well.
Mason City is home to the Iowa Traction Railroad. The IATR is one of the last surviving electric interurban railroads in the U. S., and the only one that still uses electric locomotives to haul freight in regular service.
The city also has a municipal airport, from which Buddy Holly, Ritchie Valens and The Big Bopper took off on the night of February 3, 1959 after a concert at the Surf Ballroom in nearby Clear Lake, Iowa, only to crash in a historic event later referred to as the Day the Music Died.