More thunderstorms are expected to hit the central and southern North Island on Sunday.
MetService spokesman John Crouch says the combination of another warm humid day and light winds will lead to cloud build-ups, producing scattered heavy showers and thunder.
Areas affected include southern Taupō, Taumarunui, Taihape, inland Whanganui, northern Manawatū, the western ranges of Gisborne and
Heavy downpours - 20-40mm per hour - and even hail are possible.
Such heavy rainfall can cause flash floods and streams and rivers can rise abruptly. People should also watch for slips.
Driving could become hazardous and motorists are advised to stop until the rain lessens.
For information on preparing for and keeping safe during a storm, see the Civil Defence Get Ready Get Thru website.