Summer is just over a week away but MetService is warning it's going to get "pretty intense" with heavy rain and thunderstorms forecast to lash the North Island.
MetService said an unstable northwest flow with embedded fronts will bring periods of heavy rain and possible thunderstorms to many parts of the country on Tuesday and Wednesday.
MetService meteorologist Angus Hines told AM Kiwis in the North Island should be prepared for "pretty intense" weather on Tuesday afternoon.
"The rain is returning later on today, I can assure you of that, generally sliding southwards across the North Island, so there has already been some heavy rain and really active thunderstorms across Northland this morning," he told AM fill-in co-host Amanda Gillies.
"That's set to reach Auckland around the middle of the day today but it's really this afternoon in the evening when the wet weather, the active weather gets much more widespread across the North Island."
The wild weather is coming south from the top of the North Island, which will give it "extra fuel" to provide thunderstorms and heavy rain, Hines said.
"You might've noticed over the last few days that even those times when it's not raining, it's quite sticky and quite muggy and that gives that feeling that it could start raining at any time and more often than not, that feeling has sort of come to fruition," he told AM on Tuesday.
"So the fact that everything's coming down from the north, that gives us that extra energy, that extra fuel to start to provide heavy rain and thunderstorms over the country."
Even though summer is just around the corner, Hines warned some places will see a drop in temperature in the coming days.
"We're looking to be sort of below average actually in parts of the South Island over the coming days, not absolutely frigid, we're a little bit late in the year for those really, really chilly subzero temperatures," he said.
"But many spots in the South Island and eventually the North Island, too, are looking to drop about five degrees over the coming days, getting down into the low or the mid-teens for the daily highs and probably dropping into the single digits for the overnight minimums."
For any Kiwis looking for some fine weather, Hines said they'll have to wait until next week.
"I would love to be able to give some good news and say that summer is just around the corner, but it doesn't really look like that," Hines said.
"We kind of get a couple of brief clearances in the outlook period … we might get some more pleasant weather on Friday and Saturday for many parts of the country, but it's short-lived.
"More rain returning to the bulk of Aotearoa on Sunday and then it looks like there might be a slightly longer nice spell of weather to kick off next week."
There are still many weather watches and warnings in place for large parts of New Zealand.
MetService said a heavy rain warning is in place for the Bay of Plenty and Gisborne until 7am on Wednesday with 140mm of rain expected.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous." MetService warned.
A heavy rain warning is also in place for the ranges of Westland until 5pm on Tuesday with 120mm of rain expected.
A heavy rain watch is in place for Northland, central North Island high country, Waitomo, North Taranaki, Buller and Fiordland until Wednesday morning.
A strong wind watch has been issued for Northland, Auckland, Great Barrier Island and Coromandel Peninsula, Bay of Plenty, Gisborne, Hawke's Bay, Wairarapa, Wellington and the Canterbury High Country.
A heavy swell warning is in place for Kapiti-Porirua Coast and Otaki to Cape Terawhiti.
