Helena Bay on Whangārei's northeast coast was hit hard by heavy rain on January 18. Video / Liv Patu
A Northland hydrology report has detailed the devastating extreme rainfall in January which caused flooding and slips.
The heavy rainfall began with a severe thunderstorm on January 18, concentrated on Northland’s east coast from Whangaruru to Ngunguru.
The coastal settlement of Ōakura, in particular, was shattered by flooding and slips, with six buildings – including the community hall – being red-stickered.
Northland Regional Council’s hydrology report for January has now put the extreme weather into perspective, measuring an average of 232mm of rain across the region, which is 299% of the long-term average for the month.
The highest rainfall total measured by the regional council was recorded at Punaruku, at Otetao Reti Marae, near Ōakura.
It recorded 608mm of rain, which is 781% of what is normally expected for the month.
Northland Regional Council's provisional rainfall report for January 2026 compares the month's rain as a percentage of normal. The image's dark shading shows how severe heavy rain hit the east coast.
Other rainfall stations with very high recordings in January were:
Ngunguru at Dugmores Rock with 511.5mm, 619% of normal
Whakapara at Puhipuhi: 466mm, 567% of normal
Hatea at Glenbervie Forest: 461.5mm, 480% of normal
Towai at Weta (north-east of Kāeo): 405.5mm, 407% of normal
Hakaru at Tara (inland Mangawhai): 358mm, 398% of normal.
Even the Northland site with the least rain in January – Kaipara’s Pouto Point – had 90.5mm, which is 199% of what is normally expected for the month.
Using climate forecasting from Earth Sciences NZ for February to April, the council report warned the risk of weather systems connected to the tropics and subtropics increases.
This could lead to more “significant rainfall events” as the season goes on, it warned.
The Ōakura Community Hall was one of the buildings devastated by heavy rain and slips in January, with 608mm of rain measured for the month. Photo / Denise Piper
Temperatures are most likely to be warmer than normal and rainfall totals are most likely to be above normal, with both having a 50% chance.
Weather systems linked to subtropics or tropics may bring heavy rainfall, the report warned.
The tropical cyclone outlook from Earth Sciences and MetService also forecast a normal-to-elevated risk of cyclones for northern New Zealand for the season, which runs November 2025 to April 2026.
This means one to two ex-tropical cyclones are likely.
The good news from this report is, with normal-to-high groundwater levels, river flows and soil moisture levels for this time of year, there is a low risk of drought conditions developing in Northland over the next three months.
Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.
