Diamondhead Lake, Iowa

As of the census of 2020,^[4] there were 371 people, 154 households, and 117 families residing in the community. The population density was 381.3 inhabitants per square mile (147.2/km²). There were 226 housing units at an average density of 232.3 per square mile (89.7/km²). The racial makeup of the community was 90.6% White, 0.8% Black or African American, 0.8% Native American, 1.9% Asian, 0.5% Pacific Islander, 0.3% from other races and 5.1% from two or more races. Hispanic or Latino persons of any race comprised 2.4% of the population.

Of the 154 households, 27.3% of which had children under the age of 18 living with them, 69.5% were married couples living together, 3.2% were cohabitating couples, 12.3% had a female householder with no spouse or partner present and 14.9% had a male householder with no spouse or partner present. 24.0% of all households were non-families. 21.4% of all households were made up of individuals, 9.7% had someone living alone who was 65 years old or older.

The median age in the community was 48.9 years. 25.6% of the residents were under the age of 20; 3.0% were between the ages of 20 and 24; 18.1% were from 25 and 44; 31.0% were from 45 and 64; and 22.4% were 65 years of age or older. The gender makeup of the community was 47.7% male and 52.3% female.