By John Lewis, Otago Daily Times
Climate scientists are predicting winter 2025 could be warmer than usual. Photo: Tom Kitchin
Electricity bills may deliver less of a hammering this winter if NIWA's outlook for the next few months comes to fruition.
It shows temperatures from June to August are "very likely" to be warmer than average this winter, meaning fewer cold snaps and frosts than usual.
NIWA National Climate Centre forecasting principal scientist Chris Brandolino said El Nino Southern Oscillation (ENSO) conditions in the tropical Pacific remained neutral at present, but there were "residual signals" that indicated weak La Nina conditions were persisting.
Occasional La Nina-like atmospheric patterns might still emerge over the next three months, he said. "However, international guidance indicates about a 70 percent chance for the tropical Pacific to remain in an Enso-neutral state over the next three-month period."
He said higher-than-normal atmospheric pressure was expected to the east of the country, leading to northeasterly flow anomalies that might shift to a more northwesterly direction towards the end of the three-month period.
That means seasonal air temperatures are expected to be above average across all New Zealand regions for the winter season.
"While cold snaps and frosts will occur, they are expected to be less frequent than usual."
On the West Coast, Southern Alps and foothills, inland Otago, and Southland, temperatures were very likely to be above average, he said.
Rainfall totals, soil moisture levels and river flows are about equally likely to be near normal or above normal.
Temperatures were also very likely to be above average along coastal Otago, he said.
"Rainfall totals are most likely to be in the near normal range, and soil moisture levels and river flows are about equally likely to be near normal or above normal."
Brandolino said for the remainder of the calendar year, ENSO-neutral conditions were expected to persist.
"The guidance available, however, suggests the possibility for La Nina conditions to return by summer 2025-2026."
La Nina can bring more northeasterly winds to New Zealand, leading to drier conditions in the south and southwest of the South Island.
- This story was first published by Otago Daily Times
