‘A tale of two islands’: Where it’s been wettest and driest this summer

Campers were forced to abandon holidays at beachside campsites in Coromandel and Northland ahead of a storm hitting days into the new year. Photo / Alan Gibson.

New Zealand’s mid-summer state has been dubbed a “tale of two islands” - with expanding dryness in the south, but more downpours in store for an already rain-soaked north.

Niwa forecaster Ben Noll said soil moisture maps laid bare the starkly different summer seasons that northern and southern regions have been experiencing over the country’s third consecutive La Niña summer.

Swathes of the South Island were now parched, with large pockets recording soil moisture deficits of more than 130mm.

Niwa’s latest Hot Spot Watch report stated that, compared with normal for this time of year, the driest soils could be found in the upper West Coast, Banks Peninsula, Fiordland, coastal Southland and Stewart Island.

With little rain on the cards next week, those dry spots were expected to expand.

Although no regions were yet in meteorological drought, Banks Peninsula, Fiordland and a long stretch of the Otago coastline already met NZ Drought Index thresholds for dry conditions.

Soil moisture levels across New Zealand, as at Saturday. Image / Niwa

“Otago, Southland, maybe some pockets within Canterbury ... if there’s going to be drought, those are the areas we’d be focusing our attention on.”

That pattern was consistent with La Niña, an ocean-driven phenomenon that traditionally delivered more north-easterly winds and rainy conditions to North Island’s northeast, and drier conditions to the south and south-west of the South Island.

“This is the kind of summer where, as a holiday-maker, you’d much prefer to be in Invercargill than Cape Reinga.”

In the North Island, soil moisture levels were unusually high virtually everywhere – but especially across the East Coast, Waikato, Bay of Plenty, Taranaki and about the ranges west of Hawke’s Bay.

“As we go through the season, the North Island will likely get these semi-regular influxes of moisture from the tropics and sub-tropics, which is going to keep things looking pretty healthy,” Noll said.

“While the north is seeing a much-needed spell of settled weather, we may find ourselves back into a more unsettled regime toward the end of January and into early February.

“Those areas would then have yet another top-up of moisture, when they’d hardly had a chance to dry out.”

Niwa’s climate outlook for the first three months of 2023 picked above-normal rainfall in the east of the North Island, below normal in the west of the South Island, near normal in the west of the North Island, and about equally likely to be near normal or above normal elsewhere.

The dominant La Niña system, which has also brought widespread warmth this season, was predicted to fade out by mid-Autumn.

What NZ farmers think about droughts, climate change

Meanwhile, a new analysis finds Kiwi farmers expect climate change to bring worsening droughts – and those most worried are more likely to back efforts to slash emissions.

While women and those with more education appear to hold the greatest concerns about drought events becoming more frequent and severe, the study also found that general awareness was now shared by all but a minority of farmers.

To examine the link between drought and farmers’ views toward climate change, Manaaki Whenua-Landcare Research and Victoria University researchers delved into data from a two-yearly nationwide sector survey that gathered nearly 4000 responses.

Study co-author Professor Ilan Noy, of Victoria University, said increasing drought remained the biggest climate risk to farmers – especially in key agricultural regions Waikato and Canterbury.

Major recent events had highlighted the economic havoc they could wreak.

A 2008 dry spell cost the sector more than $1b and cut the country’s sheep numbers by more than a tenth, while a severe drought in 2013 disrupted dairy production enough to lower annual GDP by 0.3 per cent.

Under the quickening pace of global warming, some regions have been growing drier - many of them in the northern North Island – while other areas, like the south and west of the South Island, have been seeing more rainfall.

More frequent and severe drought is emerging as one of climate change's clearest signals in New Zealand. Photo / George Heard

Unsurprisingly, Noy said, farmers’ past experience of drought correlated to climate beliefs.

“There are some regional differences - with a bit more scepticism about the links between droughts and climate change in some regions - but overall, the large majority of farmers are perceiving an increasing risk from droughts because of climate change.”

In line with other studies, older farmers expected drought to increase in frequency and intensity more than their younger colleagues.

“Female farmers are more concerned about future droughts than male farmers,” the study authors reported.

“Moreover, if farmers have higher education, they tend to perceive more future increase in drought frequency and intensity by 2050.”

Their analysis, published in the journal Environmental Hazards, also showed most farmers reported having a “moderate” focus on being more resilient toward climate change over the next five years, while also using water more efficiently and reducing their emissions.

Those farmers who perceived higher drought risks were also more likely to support - or plan for – mitigation, Noy said.

“However, it is important to note that they are probably not doing so because of the increasing risk they are facing, but because they are just more aware of the general global risks that climate change is posing to agriculture, and perceive that they need to contribute to the global effort to avert this,” he said.

“Farmers do care about droughts, and do care about climate change.”

The findings come at a time the agriculture sector prepares to be priced on farm emissions from 2025, with farm sequestration to be separately recognised under the Emissions Trading Scheme.

Here, Noy said the study results were relevant in as much as they confirmed most farmers were aware of the risks that climate change was posing for their own operations, and therefore more likely to support mitigation.

“It probably also suggests that the opposition from some farmers to mitigation, and a general disbelief in the risks posed by climate change, is very much a small minority opinion within the farming community,” he said.

“At least in this aspect, the message is quite positive; the one sector that has been perceived as more reluctant to undertake the mitigation that is necessary because of this globally unprecedented challenge is actually on board.”