After causing wide spread damage in Fiji, Tonga and Samoa last week, ex-tropical cyclone Gita hit New Zealand's upper South Island this afternoon (20 February, NZDT), prompting airline carrier Air New Zealand to ground all flights into and out of Wellington.
Air New Zealand grounded all flights to the capital city of Wellington at 2.45pm (1.45am GMT) as heavy winds and rain cause unsafe travel chaos.
Christchurch Mayor Lianne Dalziel declared "the full impact of the storm will be felt overnight and tomorrow morning".
She is urging people to get off the roads and to a safe place before darkness falls, which was one reason for declaring the state of emergency now.
Residents have been told to expect winds of up to 150 km/hour and to avoid travel.
Prime Minister Jacinda Ardern said that troops had been sent out to areas that were likely to be hardest hit by the storm.
"If you are in a flood-prone area, particularly if your home was flooded, or close to flooding, in the July storm past year, you should consider evacuation before the worst of the storm hits tonight".
She added that the national Civil Defence office in Wellington were also on standby.