Flash flooding, slips and hazardous driving conditions are predicted in the North Island today as a powerful active front moves down the country, bringing heavy rains and possible thunderstorms.
Rain is expected to continue through to Tuesday and Wednesday for several parts of the country caught in the wild weather.
MetService said the active front was expected to move south over the North Island today and bringing a period of rain and heavy falls.
A moderate risk of thunderstorms is likely for most of the upper North Island from Auckland to Taihape.
"The moderate risk of thunderstorms is expected to ease in Auckland and the Coromandel Peninsula later this afternoon but persist into the evening farther south, from Waikato to Taranaki, the central high country, Bay of Plenty and the ranges of Gisborne and Hawkes Bay," MetService said.
A low risk of thunderstorms was expected over a broader area including the far south of Northland, and parts of the south and east of the North Island as well as about parts of Marlborough, Nelson, Buller and northern Westland, MetService said.
A heavy rain warning was in place for Wairarapa, Tararua District, Eastern Marlborough and also the sounds until 10pm Monday.
Up to 180mm of rain was expected to hit the ranges and up to 120mm on the coast.
The wet weather had meant Auckland's annual Santa Parade was postponed due to the poor conditions.
Organisers confirmed that the parade will be delayed until next Sunday, December 2 due to severe weather warnings.
The parade has not been cancelled since the 1990s, the organisers said.
Looking ahead, the complex low-pressure system over New Zealand was forecast to slowly move away to the east on Wednesday.
There was high confidence, 60 per cent chance, that rainfall accumulations would reach warning criteria in Dunedin, North Otago, Canterbury, Marlborough, the eastern hills of Wellington and Wairarapa on Monday.
"Meanwhile, the confidence for warning amounts of rain about the northwestern ranges of Nelson and Mount Taranaki is moderate on Monday," MetService said.
"On Wednesday and early Thursday, there is moderate risk of warnable amounts of rain in Hawkes Bay and Gisborne."
On Tuesday, there was a low risk that rainfall would reach warning criteria in Northland, Auckland, Coromandel Peninsula, Waikato, Bay of Plenty and the central North Island high country.
Whangarei: Rain, possibly heavy and thundery, easing to showers by afternoon. Northwesterlies.
High 24C Low 14C
Auckland: Rain turning to showers afternoon, possibly heavy and thundery until evening. Northeast turning northwest midday.
High 23C Low 14C
Tauranga: Rain, possibly heavy and thundery, easing late evening. Northerlies.
High 21C Low 13C
Whanganui: Cloud increasing morning, then occasional rain. Southeast winds.
High 24C Low 13C
Napier: Rain developing late morning, possibly heavy, then easing evening. Easterlies strengthening.
High 19C Low 14C
Wellington: Cloud increasing, rain from evening. Southerlies strengthening this afternoon.
High 22C Low 14C
Christchurch: Low cloud with rain, could be heavy. Easterlies.
High 16C Low 11C
Dunedin: Overcast with drizzle. Easterlies.
High 14C Low 10C
Invercargill: Fine breaks. Brisk easterlies.
High 19C Low 10C