The northern coastline of Australia is one of the most cyclone-prone areas of the world.
 
Communities in the region are threatened by tropical cyclones every season, with a very real risk to property and life. A tropical cyclone's effects vary depending on its intensity, so it's important you understand the hazards involved and the potential damage a tropical cyclone can cause. The intensity of tropical cyclones is described according to the numerical scale of 1 to 5, with 5 being the highest rating.

These intensity ratings are based on the maximum wind gusts associated with the cyclone, which usually occur around the centre, known as the eye.

Tropical cyclones can intensify rapidly. There have even been occasions when a category 1 cyclone has become a category 5 within a day. It's essential that your plans to evacuate or take shelter are made well before the predicted arrival of the strongest winds.

A Category 1 tropical cyclone has estimated wind gusts up to 125 km/h. These wind speeds can damage crops, blow over small unsecured objects and cause boats to drag their moorings.

A Category 2 cyclone has estimated gusts between 125 and 164 km/h. These wind speeds will cause damage to homes, blow over large trees and make it dangerous to be outside.

A Category 3 cyclone has estimated gusts between 165 and 224 km/h. These destructive wind gusts can rip roofing from buildings, destroy caravans, cause large debris to fly through the air; and the risk of injury is real. If a cyclone reaches category 3 intensity, it is referred to as a severe tropical cyclone and is often the point when the characteristic eye of a cyclone will become clear on satellite images.

A Category 4 cyclone has estimated gusts of between 225 and 279 km/h. These winds are very destructive, causing significant roofing and structural damage to buildings, dangerous airborne debris and widespread power failures.

A Category 5 cyclone has estimated gusts of 280 km/h and above. Winds at this speed are extremely dangerous and cause widespread destruction.

Along with powerful winds, tropical cyclones can bring heavy rain and storm surge, creating life-threatening situations in addition to the cyclone itself. Heavy rainfall can cause flooding, and it's not always the case that the most intense cyclones bring the heaviest rainfall. Storm surges associated with cyclones can have dangerous and devastating effects on coastal areas, with the level of inundation highly dependent on the tide levels around the time the cyclone crosses the coast.

All tropical cyclones are dangerous, regardless of their category; so be prepared, listen to local authorities and stay updated via the Bureau's website. Then you always have the latest cyclone information.