Severe Cyclone Donna has just spiked at Category 5 with winds sustained at 215km/h and gusting 260km/h, making Donna the strongest ever May cyclone recorded in the entire Southern Hemisphere.

CNN's Severe Weather Team just broke the news to WeatherWatch.co.nz a short moment ago. (WeatherWatch.co.nz is a CNN affiliate).

'Official updates out of the Fiji MetService may not capture this current spike with their updates limited to a few set times across the day,” says the latest update from the weather organisation.

'However, they also confirmed the air pressure had fallen a lot overnight to just 948hPa. It may be even lower than this now too.

Donna is still likely to weaken towards New Caledonia in the next 48 hours or so.