Intense gusts reaching speeds of up to 155km/h (96mph) have resulted in nearly 90,000 households without power and forced agencies to cancel more than 100 aircraft departures, as reported by regional news sources.
The gales are affecting the whole South Island and lower areas of the North Island, according to the weather forecasting body.
The nation's agencies have announced rare severe gust advisories - the top caution category - in key areas such as Canterbury and Wellington.
Residents have been encouraged to avoid going outside, stay off roads, and make arrangements for additional power and communication outages.
Extensive Destruction and Crisis Measures
This outage appears to be affecting households mostly in the southern region, while agencies say that energy was being gradually reinstated.
Domestic outlets have reported that in some places homes have lost their roofs, while trees and electricity poles have been brought down by the gusts.
In Wellington, a individual was fatally injured after being struck by a tree branch at a popular trail walking spot on earlier this week.
Meanwhile in Wellington, a woman was pushed toward moving cars on a street by a powerful blast, in a incident that was recorded in a widely shared car camera footage.
Flights entering and leaving the city have been halted due to the gusts, while various routes and public facilities are shut down.
At the same time authorities in Canterbury have issued a emergency situation, to support emergency management operations.
Labor Protests Amid Severe Conditions
The wild winds on Thursday occur while tens of thousands of school staff, physicians and civil servants are engaged in what has been termed a "mega strike", calling for higher wages and enhanced employment terms.
But the extreme weather has compelled them to change various scheduled activities, with several external protests shifted to interior venues or called off.
Similar gusts are affecting the nearby nation, causing a period of extreme heat to the remote areas.
Officials have announced flame prohibitions for apprehension regarding bushfires.
