When is cyclone season in Australia?
The official season spans November to April and peaks after Christmas. Here is where cyclones form, how BOM grades them, and how to read the watches and warnings.
Australia's tropical cyclone season officially runs from 1 November to 30 April, with the greatest risk between January and March. Cyclones form over the warm tropical waters off northern Australia — the coasts of Western Australia, the Northern Territory and Queensland. The Bureau of Meteorology (BOM) says around 11 tropical cyclones occur in the Australian region each year, with about four crossing the coast.
When exactly is cyclone season?
The official Australian tropical cyclone season spans the six warmest months, 1 November to 30 April. Sea-surface temperatures across the tropics need to be roughly 26.5°C or higher to fuel a cyclone, which is why the season tracks the northern wet season. Activity typically ramps up after Christmas, and the peak months are January, February and March. Cyclones can occasionally form outside these dates, but they are rare.
Where do Australian cyclones form and strike?
Cyclones develop over three main areas: the waters off the north-west coast of Western Australia (the Pilbara and Kimberley), the seas north of the Northern Territory around the Timor and Arafura Seas, and the Coral Sea off Queensland. The north-west WA coast between Broome and Exmouth is the most cyclone-prone stretch of the Australian coastline. BOM runs three Tropical Cyclone Warning Centres — in Perth, Darwin and Brisbane — each responsible for its own slice of the coast.
How are Australian cyclone categories measured?
Australia uses its own five-point scale, and it is important to understand that it is based on the strongest wind gust, not the sustained wind used by the American Saffir–Simpson scale. That means an Australian "Category 3" is not directly comparable to a US "Category 3". Categories 3, 4 and 5 are all classed as severe tropical cyclones.
| Category | Strongest gust | Typical impact |
|---|---|---|
| 1 | Less than 125 km/h | Minor damage; some crop and tree damage |
| 2 | 125–164 km/h | Damage to some crops, trees and caravans |
| 3 (severe) | 165–224 km/h | Roof and structural damage; power failures likely |
| 4 (severe) | 225–279 km/h | Widespread structural damage; dangerous airborne debris |
| 5 (severe) | More than 280 km/h | Extremely dangerous; widespread destruction |
For reference, Cyclone Tracy, which devastated Darwin on Christmas Eve 1974, and Cyclone Yasi, which crossed the north Queensland coast as a Category 5 in February 2011, remain the benchmark disasters against which northern communities measure their preparations.
What is the difference between a watch and a warning?
BOM issues two escalating products. A Tropical Cyclone Watch is issued when a cyclone could affect coastal communities within 48 hours, but is not expected within 24 hours. A Tropical Cyclone Warning is issued when gales or stronger winds are expected within 24 hours. Warnings are updated frequently — often every three hours, and hourly as the system nears the coast — and are the single most important source once a cyclone threatens.
Does La Nina mean more cyclones?
Yes, the odds shift with the background climate. During La Nina years, the Australian region tends to see more tropical cyclones and an earlier start to the season. During El Nino years, cyclone numbers tend to be lower and the first cyclone often forms later. These are tendencies, not guarantees — it only takes one landfall to make a severe season for the community that gets hit, so preparation should never depend on a quiet outlook.
How do the models forecast track and intensity?
Cyclone track forecasting has improved dramatically, but intensity forecasting remains one of meteorology's hardest problems, and rapid intensification near the coast can catch communities out. This is exactly where comparing models earns its keep. At checkweather.io we place ECMWF (European), NOAA's GFS (American) and DWD's ICON (German) side by side and translate their agreement into a plain-English forecast confidence score. When the models cluster tightly on a landfall point, confidence is high; when they spread the track over hundreds of kilometres, the score falls and you know the situation is genuinely uncertain. For official watches, warnings and the forecast track map, we always link straight through to the Bureau of Meteorology, which is the only authority for cyclone warnings in Australia.
Why is storm surge and rain the bigger killer?
The wind gets the headlines, but water causes most cyclone deaths and damage. Storm surge — the dome of seawater a cyclone pushes ashore — can inundate low-lying coastal communities, and it is at its worst when landfall coincides with a high tide. Away from the coast, the real threat is often rainfall: a cyclone that weakens into an ex-tropical low can still dump enormous totals as it moves inland, triggering major river flooding hundreds of kilometres from where it crossed the coast, sometimes days later. That is why BOM's warnings cover flood and surge as well as wind, and why "the cyclone has been downgraded" never means the danger has passed.
How should you prepare for cyclone season?
Before the season starts, trim trees, secure loose items around the yard, check the roof, and put together an emergency kit with water, food, a torch, batteries, a battery radio and important documents. Know your nearest shelter and evacuation route, and understand whether your property sits in a storm-surge or flood zone. When a warning is issued, stay indoors away from windows, and never venture out during the eerie calm of the eye — the destructive winds return from the opposite direction within minutes. Above all, act on official advice early: roads flood and shelters fill well before the worst weather arrives.