Cairo Township was organized in 1868, and named, directly or indirectly, after Cairo, in Egypt.
According to the United States Census Bureau, the township has a total area of 34.2 square miles (89 km2), of which 33.9 square miles (88 km2) is land and 0.2 square miles (0.52 km2) (0.64%) is water.
As of the census of 2000, there were 271 people, 97 households, and 76 families residing in the township. The population density was 8.0 people per square mile (3.1/km2). There were 99 housing units at an average density of 2.9/sq mi (1.1/km2). The racial makeup of the township was 94.83% White, 0.74% Native American, 1.85% from other races, and 2.58% from two or more races. Hispanic or Latino of any race were 2.95% of the population.
There were 97 households, out of which 36.1% had children under the age of 18 living with them, 70.1% were married couples living together, 4.1% had a female householder with no husband present, and 21.6% were non-families. 20.6% of all households were made up of individuals, and 3.1% had someone living alone who was 65 years of age or older. The average household size was 2.79 and the average family size was 3.21.
In the township the population was spread out, with 31.4% under the age of 18, 5.5% from 18 to 24, 30.6% from 25 to 44, 22.5% from 45 to 64, and 10.0% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 106.9 males. For every 100 females age 18 and over, there were 111.4 males.
The median income for a household in the township was $38,750, and the median income for a family was $41,375. Males had a median income of $28,929 versus $25,625 for females. The per capita income for the township was $17,310. About 9.3% of families and 13.3% of the population were below the poverty line, including 14.9% of those under the age of eighteen and none of those 65 or over.
- “U.S. Census website”. United States Census Bureau. Retrieved 2008-01-31.
- “US Board on Geographic Names”. United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- Upham, Warren (1920). Minnesota Geographic Names: Their Origin and Historic Significance. Minnesota Historical Society. p. 456.