Westland District has the largest number of lightning strikes in New Zealand, with almost 50% more than anywhere else in the country.
An average of 9,060 “cloud to ground” lightning strikes were recorded annually in Westland from 2001 to 2020, according to a report by the NZ Herald, which cited data from Metservice. In second place is Canterbury, with 5,530 average annual strikes.
Fiordland, Bay of Plenty and Waikato rounded out the top five. Bay of Plenty was the only area outside of South Island in the top five. Auckland’s annual average is 900 and Wellington’s is 163. Christchurch had the fewest lightning strikes recorded at just 85 annually.
Deaths due to lightning strikes in New Zealand are quite rare, only occurring once every five to 10 years.
According to Lisa Murray, Metservice’s head of weather communications, Westland’s geography makes it an ideal place for lightning to form.
“Most of our weather comes from the west. As that weather moves on to the country it gets pushed up over the land, and on the West Coast, in particular, it goes from sea level right up into the Southern Alps really quickly,” Murray told the NZ Herald. “When you lift air, it gets colder as you go up into the atmosphere and colder air holds less moisture so that excess moisture comes out as rain that can cause clouds. Then you can get these clouds turning into towering cumulus and then cumulus nimbus, which are those thunderstorm clouds.”
While Canterbury has the second-largest number of lightning strikes, 85% of those occurred in the high country, mostly sparing the plains.
While lightning strikes in Christchurch are rare, it is exposed to a different type of thunderstorm.
“We call them summer thunderstorms,” Murray said. “The clouds bubble up due to the heat of the day. The air warms and rises and that gives the uplift, rather than the mountains.”
One such storm struck South Canterbury on November 20, 2019. A hailstorm hit Timaru, dropping golf ball-sized hailstones and dealing widespread damage to vehicles and buildings. Around 12,000 motor insurance claims and 5,800 home and contents claims were filed, with the total insurance bill exceeding $170 million.
