Weather: Forecasters warn large weather system set to bring heavy rain to parts of NZ

• Large weather system likely to bring “atmospheric river”, significant rain to some areas this week.
• Heavy rain, strong winds tipped, especially in western and northern parts of both islands.
• Overnight temperatures set to soar this week, reaching the mid-to-high-teens for many areas.

Forecasters are warning a large weather system is likely to bring an “atmospheric river” to New Zealand this week.

It’s set to be “one of the more promising” rain-bearing systems seen in a while amid “dire” ongoing drought conditions throughout the North Island.

target="_blank">MetService recorded parts of Northland, Auckland, Bay of Plenty and Waikato had received less than half the typical March rainfall.

“It would seem that March is carrying the baton, continuing the legacy of a dry 2025 so far,” meteorologist Mmathapelo Makgabutlane said.

But much-needed rainfall is expected in the second half of the week, with a large weather system approaching from the Tasman Sea ”one of the more promising rain-bearing weather systems we have seen in a while”.

MetService said settled weather would prevail for the start of the week — except for the odd shower for some spots — but Wednesday into Thursday would mark a shift to wetter conditions nationally.

“Western and northern parts of both the North and South Islands may see heavy rain, while strong northerly winds are also possible, particularly for the North Island,” Makgabutlane said.

While relatively quiet weather starts the week, it'll be a much different story from about Wednesday.

Low pressure over the Tasman is likely to induce a flow of moisture, or atmospheric river, from the tropics.

Keep up-to-date with watches & warnings from @MetService. pic.twitter.com/VnJ1oAHDhY

— NIWA Weather (@NiwaWeather) March 30, 2025

“Whether the rain and wind arrive late Wednesday or Thursday, the second half of the week will be the one to watch.”

Western parts of the North Island had been relying on spotty showers that had only brought patchy rainfall, but this system looked to bring more widespread wet weather, she said.

“It will take more than this one system to make a meaningful difference to the current dry situation. However, it is a step in the right direction.”

Forecaster Niwa said low pressure over the Tasman would bring an atmospheric river south from the tropics.

Meanwhile, warm, humid nights are also tipped for later this week as a moist northerly airflow covers the country.

MetService said overnight temperatures in the mid-to-high-teens could be expected for many — a drastic change from recent single-digit temperatures that had brought frost to some areas.

“Auckland can expect night-time lows of around 18C for most of this week, while Christchurch will only drop to 15C on Friday morning — its warmest overnight temperature in over a month,” the forecaster said.

“The last time much of the country saw overnight temperatures this warm was mid-February, with a similar system from the Tasman Sea. The result will be very different feeling weather compared to the cold fronts from the southwest that have been the norm recently.”