Air NZ flights have been cancelled in Wellington, while a state of emergency has been declared in Christchurch.
The storm approaching New Zealand has changed its course slightly, moving further south.
New Zealand Defence Force personnel have been deployed to the areas expected to be hardest hit by tropical cyclone Gita.
Air New Zealand is warning of severe disruptions to flights at five airports.
Over 57 schools and early childhood education centres are closed at top of the South Island, all schools in Buller District closed until Thursday.
Senior meterologist Lisa Murray said heavy rain should ease off Wellington and will hit Christchurch instead.
The latest severe weather update upgraded watches for heavy rain in Christchurch, Banks Peninsula and North Otago to full warnings.
Source: RadioNZ
