Nemaha is a city in Sac County, Iowa, United States.

[3] According to the United States Census Bureau, the city has a total area of 0.07 square miles (0.18 km2), all land.

There were 34 housing units at an average density of 403.3 per square mile (155.7/km2).

There were 36 housing units at an average density of 514.3 per square mile (198.6/km2).

The racial makeup of the city was 88.2% White, 3.5% African American, 1.2% Asian, and 7.1% from other races.

24.2% of all households were made up of individuals, and 6% had someone living alone who was 65 years of age or older.

The racial makeup of the city was 97.06% White, 0.98% Native American, and 1.96% from two or more races.

28.6% of all households were made up of individuals, and 9.5% had someone living alone who was 65 years of age or older.

There were 8.3% of families and 9.5% of the population living below the poverty line, including no under eighteens and none of those over 64.