The following table shows the development of the number of inhabitants in Omak and surrounding areas according to census data of the United States Census Bureau. The municipalities of North Omak and Riverside are included in both Greater Omak and its zip code. Okanogan is also a member municipality of Greater Omak, but maintains a separate zip code.
Although there has been no official population count for homelessness in the city, there have been several efforts to provide service and homes for the homeless people of Greater Omak, by Okanogan County Community Action Council. There is a food bank that operates in Omak.