Tropical Storm Erin is expected to become a hurricane later today, Aug. 15, and a Category 4 hurricane with maximum sustained winds of 130 mph over the weekend. A major hurricane is a Category 3 or stronger, with maximum sustained winds of at least 111 mph.

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.