Hurricane Helene made landfall near Perry, Florida, as a Category 4 storm with sustained winds of 140 mph (230 km/h) and higher gusts.

It is the strongest hurricane on record to land in Florida’s Big Bend. The high winds and heavy rainfall could cause widespread power outages and flooding in the southeast, where the ground is already saturated from the previous day’s storms.

But what do these categories mean?

Hurricanes are rated from 1 to 5 on the Saffir-Simpson Hurricane Wind Scale, based on their wind speed. The damage is exponential as wind speed increases, meaning a strong Category 3 storm can cause up to 60 times as much damage as a weak Category 1 storm.

These are the main risks you can expect with each category:

Category 1: 120-150 km/h

Persistent winds are enough to blow shingles off roofs and damage gutters and vinyl siding. These winds can also uproot trees and down branches, causing power outages and more property damage. They can also damage power lines.

Category 2: 96-180 km/h

Such strong winds can cause up to twenty times the damage of a Category 1 storm, including major damage to a home’s roof and siding.

Numerous trees and power lines will most likely be damaged, blocking roads, damaging property and causing power outages for days, if not weeks.

Category 3: 180-200 km/h

Now wind damage in the “major hurricane” area is much more widespread. Well-built homes and other buildings can sustain extensive damage, and roofs will sustain heavy damage. Numerous trees will be damaged or uprooted. Electricity and water may be cut off for several days.

Category 4: 210-250 km/h

Catastrophic damage could result from these winds. Well-built homes will be severely damaged, with most of the roof blown away. Trees and power lines will fall. Water and electricity supplies can be out for months, while the hardest-hit places are uninhabitable for weeks.

Category 5: 250 km/h or higher

These are the most powerful storms on Earth. Most well-built homes will be destroyed, and many will be stripped to their foundations. Power outages could last for months and the worst affected areas could be uninhabitable for months.