Northern New Zealand is at normal to higher-than-normal risk of a tropical cyclone for the 2024/25 season, Niwa and the MetService say.

The country is not often affected by cyclones, but the services say 0-1 are expected between November and April, representing a "normal-elevated" risk level.

They say between six and 10 named cyclones could hit the Southwest Pacific during the season, with nine being the long-term average.

"The NIWA and MetService assessment of tropical cyclone1 (TC) activity for the coming season indicates normal to below normal activity," they said in a statement.

"For the coming season, significant differences are expected between the western and eastern halves of the basin."

Pacific Islands to New Zealand's west were also at higher risk, with Solomon Islands and New Caledonia likely to see 2-3 cyclones during the season.

Papua New Guinea, Vanuatu, Fiji, Tonga, Wallis & Futuna, Samoa and American Samoa, and Niue were all expected to face 1-2 cyclones.

However, that was only higher than usual for Papua New Guinea, Solomon Islands and northern New Zealand.

Countries and territories to the east - from Fiji to the Pitcairns - were at normal-reduced, reduced, or unlikely risk.

A graphic showing the Niwa/Metservice assessment of the number of cyclones expected to hit the Southwest Pacific basin for November 2024 to April 2025. Photo / Niwa : MetService

The two agencies produced the report together, with Niwa (the National Institute of Water and Atmospheric Research) thanking MetService for its input.

It marks an early tangible sign of collaboration, after the government announced plans for a merger that would see Niwa taking over MetService - but with the latter retaining responsibility as New Zealand's authorised meteorologist.

The former Meteorological Service was split in 1992, with Metservice taking over day-to-day forecasting and NIWA - the National Institute of Water and Atmospheric Research - taking over climate research and longer-term forecasts.

It was hoped this would bring an end to a long-running rivalry between them.

- RNZ