File photo of fog in Auckland. Photo: RNZ / Finn Blackwell
Airlines are working through a backlog of delayed flights at Auckland Airport due to thick fog blanketing the city.
About 37 regional flights were cancelled and many others others delayed, with eight main trunk domestic flights also delayed after restrictions were put in place at the airport just before 2am.
Fog restrictions were lifted later on Monday morning, and flights unable to take off due were departing, but passengers faced delays.
Auckland Airport said international flights were not affected.
Thuderstorms light up skies across the country
It comes after severe thunderstorms at the weekend caused heavy rain and lightning over much of the country.
Aotearoa was struck by lightning almost 60,000 times.
MetService meteorologist Mmathapelo Makgabutlane said a large weather system moved across New Zealand on Saturday and Sunday.
She told Morning Report most of the country would have noticed frequent lightning strikes.
MetService warned it was not over yet and gnarly nor'westers would continue from Monday.
It issued an orange heavy rain warning for the Canterbury Headwaters south of Arthur's Pass from late Monday, along with a heavy rain watch for the ranges of Westland and the Otago headwaters.
An orange wind warning was issued for the Canterbury High Country from Monday evening and a strong wind watch for Wellington and Wairarapa south of about Carterton was in place for Tuesday.
Makgabutlane said changeable weather was to be expected as the southern hemisphere moves into spring.