[6] Allison's longitude and latitude coordinates in decimal form are 42.753466, -92.794599.

[7] According to the United States Census Bureau, the city has a total area of 2.93 square miles (7.59 km2), all land.

There were 466 housing units at an average density of 159.0 per square mile (61.4/km2).

Hispanic or Latino persons of any race comprised 1.3% of the population.

There were 470 housing units at an average density of 160.4 per square mile (61.9/km2).

The racial makeup of the city was 99.4% White, 0.1% Asian, and 0.5% from two or more races.

32.3% of all households were made up of individuals, and 19.6% had someone living alone who was 65 years of age or older.

There were 454 housing units at an average density of 154.0 per square mile (59.5/km2).

33.0% of all households were made up of individuals, and 23.1% had someone living alone who was 65 years of age or older.