After battering Vanuatu at the weekend, Cyclone Donna has grown to become the strongest May cyclone to hit the Southern Hemisphere.

CCN's Severe Weather Team said the Pacific cyclone spiked at Category 5 - the strongest category - on Monday morning.

Cyclone Donna covers Vanuatu's vast archipelago. Credit:Vanuatu Meteorological Service

CNN's Severe Weather Team said it had measured sustained winds of 215 kilometres an hour, with gusts up to 260kmh.

Earlier on Monday, Donna was consistently hitting wind speeds of 175kmh, which put it on par with 1986's Cyclone Nadu - the strongest May cyclone on record in the South Pacific.