Ever since the conclusion of the Otago Goldrush in the 1860s, New Zealand’s European population growth has experienced a steady ‘Northern drift’ as population centres in the North Island have grown faster than those of New Zealand’s South Island. This population trend has continued into the twenty-first century but at a much slower rate. While the North Island population continues to grow faster than the South Island, this is solely due to the North Island having a higher natural increase (i.e. births minus deaths) and international migration; since the late 1980s, the internal migration flow has been from the North Island to the South Island. In the year to June 2020, the North Island gained 21,950 people from natural increase and 62,710 people from international migration, while losing 3,570 people from internal migration.

The North Island has a larger population than the South Island, with the country’s largest city, Auckland, and the capital, Wellington, accounting for nearly half of it.