In 2022, the population of Nemaha was 66, a 1.49% decrease year-by-year from 2021. Previously, in 2021, Nemaha's population was 67, a decline of 0.00% compared to a population of 67 in 2020.
The median age in Nemaha, IA is 29.4, as per 2021 ACS 5-Year Estimates. Of the total population, 33.94% were under the age of 15, 18.35% aged 15 to 29, 33.94% aged 30 to 64, 13.76% aged 65 to 84, and 0.00% were 85 years of age and older.