Tropical cyclones have a significant impact across the Southwest Pacific, with the season starting in November and lasting through to April. This coming season, significant differences are expected between the western and eastern parts of the region, with the risk of impacts expected to be higher near and to the east of the International Date Line.
Dr Andrew Lorrey, Earth Sciences New Zealand Principal Scientist – Climate and Environmental Applications, says that there are strong indications that the Southwest Pacific is likely to see an increase in cyclone activity relative to recent years.
“During past strong El Niño events like the one that’s currently unfolding, we’ve typically seen elevated numbers of cyclones across the region, along with more activity to the east of the International Date Line. This is an area that’s usually fairly quiet.”
“Over the long term, cyclone numbers have been gradually decreasing in the Southwest Pacific, but there can be prominent year-to-year variability. Extended weather forecasts indicate we may also have an early start to the tropical cyclone season in the region this year,” says Dr Lorrey.
The tropical cyclone risk for New Zealand this year is normal, with the risk expected to be greater in late summer and autumn.
“New Zealand’s most active months for ex tropical cyclones are usually February and March, but some of them can visit us much earlier, and they can also occur beyond the end of April.
This year there is the potential that northern and western areas facing the Tasman Sea have more of a chance of experiencing a decaying storm than eastern regions,” says Dr Lorrey.
The Tropical Cyclone Outlook expects that seven to eleven named tropical cyclones could occur in the Southwest Pacific over the season.
Outlook summary
- Elevated activity: North SW Pacific, Northeast SW Pacific, Central SW Pacific.
- Normal-elevated activity: Southeast SW Pacific.
- Near normal activity: North of the Coral Sea, West Central SW Pacific, Northern
New Zealand. - Normal or reduced activity: East of the Coral Sea.
“Communities across the Pacific should pay attention to forecasts and heed official advice if a weather warning related to a tropical cyclone is issued,” says Dr Lorrey.
The Southwest Pacific Tropical Cyclone Outlook is coordinated by Earth Sciences New Zealand, and is developed with the contributions of MetService, the University of Newcastle and meteorological services across the Pacific Islands.
Read the full 2026/27 Southwest Pacific Tropical Cyclone Outlook.