New data shows the number of tropical cyclones in the Pacific has gone down in recent years — but their strength is increasing.

The Climate Division under the Vanuatu Meteorology and Geo-hazards Department says climate change is the main reason for these changes.

Acting Manager, Glenda Pakoa, explained that as the sea gets warmer due to climate change, it helps fuel stronger cyclones.

“When the sea is warmer, it acts like fuel for a cyclone. This is one reason why cyclones are becoming stronger,” she said.

Ms. Pakoa also said that while the number of cyclones is going down, wind shear — the change of wind speed and direction at different heights — is increasing. This can stop some cyclones from fully forming.

“We’ve found that wind shear has increased. Cyclones form when winds spin from the lower to upper level of the sky. If the wind becomes too strong at the upper level, it can disturb cyclone formation,” she added.

She pointed to February 2025, where four systems passed through the region, but only two became tropical cyclones. The other two could not fully develop because of changing wind patterns.

Ms. Pakoa said the situation has both good and bad sides:

“The good side is that fewer cyclones form. But the bad side is when one does form, it’s often stronger and becomes a severe tropical cyclone.”

Authorities say that whether this change is good or bad overall remains a question — but people should always be prepared during cyclone season.

Vanuatu’s cyclone season runs from November to April, but the Climate Division warns that climate change can also cause cyclones to form outside this period.