Light rain across the North Island yesterday brought little relief to farmers plagued by extremely dry soil conditions, though showers are forecast over the next few days.
NIWA declared conditions of "extreme soil moisture deficit" in Wairarapa, Hawke's Bay and Gisborne, with February rainfall just a quarter of what it normally is for those regions. The rest of the North Island was also suffering from "significant to extreme" dry conditions.
Northland was the hardest-hit region and officially declared to be in drought on Wednesday.
Light rain fell in Northland and down to Hawke's Bay yesterday morning, MetService said.
Rain gauges recorded 2mm fell in Northland, 1.4mm in parts of Hawke's Bay and just 0.5mm in Gisborne.
Spots of rain in Waikato after such a long dry spell also led to slippery driving conditions, police said.
MetService forecaster Philippa Murdoch said light spots of rain were predicted today and tomorrow for Wairarapa and up the country to Northland.
NIWA climate scientist Georgina Griffiths said the rain was likely to provide more of a morale boost for farmers than anything else.
"The bottom line is, this isn't going to make very much difference at all because soils are in deficit to the tune of 100mm of rain across the North Island."
Farmers needed a week or two of moderate, though not heavy, rain, she said.
"If you get the 100mm in one dump, then it's going to run away, because the ground's too hard to absorb it."
The long-term forecast predicted a warm autumn, with near-normal rainfall for much of the country after the patterns of high-pressure systems waned in March.
The current issues were not due to the El Nino or La Nina weather systems, but a series of blocking high-pressure systems, bringing a unique combination of low rain, lots of sunshine and high temperatures, and leading to the current soil conditions, Griffiths said.
"We do see them every 20 to 30 years like this."
Federated Farmers president Bruce Wills said he saw "not a drop" of rain at his farm north of Napier yesterday, though overcast conditions were a welcome break from the heat.
"We always get a little hopeful when rain is forecast but we just have to wait and see. Every day is one day closer. It's getting worryingly dry and it's knocking back production."