[4][5] The county is 40% rural and 60% urban owing to Nairobi's consistent growth Northwards.

Kiambu is also an economic and political powerhouse in Kenya due to its sprawling population and relatively urban and educated populace.

The long rains start in mid-March to May, and the cold season from July to August.

[6] According to the 2019 census, there is a total population of 2,417,735 in the county: 1,187,146 males, 1,230,454 females, and 135 intersex persons.

[1] The members hold office for a five-year term each, renewable during the general election.

It is temporarily located at Thika waiting for a permanent building to be constructed at Kiambu, the capital.

[12] In Kiambu County, there are 1,515 ECD centers, 948 primary schools, 365 secondary schools, 33 youth polytechnics, 165 adult education centers, one technical training institution, one technical institute of technology.

Kiambu County has a total of 505 health facilities: 108 are public, 64 faith-based, and 333 private.

[22][24] Tatu City is a special economic zone and an industrial park located in Ruiru sub-county.

Kiambu has the second largest economy in Kenya, largely due to its sprawling population and close proximity to the capital city.

[26] In 2021 a leading activist, Joannah Stutchbury was assassinated after protesting about developments in the forest.