Powerful winds hitting velocities of approximately 155km/h (96mph) have left nearly 90,000 households without power and led officials to call off over 100 air travel services, according to local media.
The gales are affecting the complete South Island and lower areas of the North Island, according to the country's meteorological service.
Officials in New Zealand have announced rare high-level wind alerts - the top caution category - in key areas including Canterbury and Wellington.
Residents have been encouraged to avoid going outside, stay off roads, and get ready for further utility disruptions.
Extensive Damage and Crisis Response
The power cut appears to be affecting residences mostly in the South Island, while authorities report that the electricity supply was being gradually reinstated.
Local media have reported that in some places structures have suffered roof damage, whereas power lines and trees have been knocked down by the winds.
Across Wellington, a man was fatally injured after being impacted by a tree branch at a frequent walking route on Tuesday.
Meanwhile in Wellington, a female was swept into moving cars on a road by a powerful blast, in a incident that was filmed in a viral dashcam video.
Air travel to and from the city have been suspended due to the winds, and certain highways and community centers are also closed.
Simultaneously Canterbury officials have issued a emergency situation, to facilitate emergency management operations.
Labor Protests During Severe Weather
The wild winds on Thursday occur while numerous of teachers, doctors and other public workers are engaged in what has been termed a "major walkout", demanding improved salaries and workplace environments.
Yet the extreme weather has compelled them to modify various scheduled activities, with several external protests relocated inside or abandoned.
Comparable winds are affecting Australia, bringing a high-temperature event to the nation's interior regions.
Officials have declared burning restrictions for fear of wildfires.
