Heavy fog forced an international flight to be diverted from Auckland Airport this morning.
The Qantas flight from Sydney was due to land in Auckland this morning but had to be sent to Wellington.
No domestic flights were affected and fog restrictions were lifted at 5am.
Cloudy, showery conditions are expected for the last day of the Matariki weekend in the upper half of the North Island.
In Northland, showers are forecast to increase this morning and there could be thunderstorms and hail, before conditions ease this evening.
After the foggy start to the day, Auckland is expected to have a few showers, possibly heavy in western areas. Similar conditions are expected in Coromandel, Bay of Plenty and Taupō.
MetService says eastern and southern parts of the North Island can expect fine weather today, with temperatures of around 15C in Wellington and 17C in Gisborne.
Most of the South Island is also forecast to have fine weather after a foggy morning. The only exceptions are Buller, Westland and Fiordland, where showers and rain are forecast.
Cloudy, showery weather is forecast for the beginning of the week, and snow is possible in the South Island.
The North Island will be partly cloudy, with possible showers on Monday, and fine in the east. There will be periods of rain or showers for most parts of the island on Tuesday and Wednesday.
In the South Island, rain is expected in most places tomorrow, with heavy falls predicted in the West Coast.
Cold southerlies on Monday and Tuesday could bring snow down to 600m in parts of the southern and eastern South Island, affecting higher roads and passes.
The best parts of the country to view the Matariki star cluster are likely to be in the east of the North Island.