Erin is the planet’s second Category 5 storm of 2025, arriving exactly four months after the first one. Cyclone Errol developed off the coast of northwest Australia and rapidly intensified from cat 1 to cat 5 strength in less than 24 hours on April 15–16. Errol then weakened drastically before coming onshore as a tropical low.

It quickly powered up from a tropical storm to a Category 5 in a single day, the National Hurricane Center said.