Massive storm clouds make their way across Auckland from the West. 10 November 2019 New Zealand Herald photograph by Dean Purcell.
Up to 3300 lightning strikes have been detected across New Zealand as a stormy cold front passes over the country - and the cooler weather is here to stay for the week.
Auckland Airport grounded flights on Sunday evening after a lightning warning was issued.
Lightning struck 8km out from the airport, which briefly grounded all flights, a spokeswoman said.
Eight domestic and regional flights were cancelled at Auckland Airport due to weather-related issues, the airport spokeswoman said.
International flights were not affected.
Elsewhere in Auckland, strong winds lifted the roof off a Waiuku garage and smashed all the windows in the house, Fire and Emergency New Zealand shift manager Craig Delly said.
Firefighters have had about five or six calls reporting trees crashing down on powerlines, but no reports of injuries, he said.
Down south, a stretch of State Highway 6 in the Tasman Region is closed after several reports of slips, flooding and tree falls between Murchison and Glenhope.
The stretch of road will be closed for some time while agencies work to clear it, police said.
Motorists should delay travel or avoid the area.
The thunderstorms are heralding a colder week across the Upper North Island.
MetService forecaster Gerard Bellam said overnight temperatures in Auckland will drop back to 11C-14C all week, in line with the November average, after an unseasonably hot 18C on Saturday night.
Over 3300 lightning strikes have been detected in the NZ region in the past two hours, with the bulk of them triggering on a front to the west of northern and central NZ https://t.co/prKU7O2R01 ^PL pic.twitter.com/mYl5EykZUT
More thunderstorms were expected overnight up to dawn on Monday, easing to showers through the rest of the day with a "moderate risk" of more thunderstorms in Auckland and Northland tomorrow.
"We have an unsettled week coming up," Bellam said.
"We are into a southwesterly flow on Tuesday. That means one or two showers - common or garden weather for Auckland really - and a dry day on Wednesday with temperatures up to 19C. Then another front travels in from Thursday so we are back to showers."
"Mean daily temperatures in Auckland in November are around 19C-20C, so I would say it's back to normal really," Bellam said.
The forecast for the whole North Island on Monday is periods of rain, heavy at times, and possible thunderstorms, easing to isolated showers and increasing fine periods from Waikato to Kapiti.
The South Island can also expect rain turning to showers in eastern areas, and showers clearing in Nelson, the West Coast and Otago-Southland.