Rain is the smaller problem
The obvious wet-season issue is water. The real issue is access. Roads close, creek crossings become impassable, parks shut sections and some tours stop running entirely.
That means the map of what you can do shrinks. A price that looks attractive in February is pricing a trip that may not include the places you had in mind.
A February price is pricing a smaller map, and the closures behind it are listed on the campervan hire in the Northern Territory depot pages.
Where the wet season actually works
It is not a write-off everywhere. The reef is at its best in the warmer months, with clearer water and calmer conditions on many days. Rainforest is greener. Waterfalls run.
The Tablelands behind Cairns stay more usable than the coast when it rains, and the gorges fill. If your plan is short drives and long stays rather than big distances, the wet season can be the better trip.
- Reef and rainforest: often better in the warmer months
- Long unsealed routes: often closed or restricted
- Remote parks: check access before you plan around them
- Heat: a planning constraint, not just a comfort one
The Tablelands stay usable when the coast is raining, and the tracks off the sealed road up there are where clearance matters, which is 4x4 hire rather than a campervan booking.
The build-up is its own season
Between the dry and the wet there is a period of heat and humidity that locals leave for. It is not dangerous if you are prepared, but it is not the trip most visitors imagine.
If you are travelling then, plan around the middle of the day, and do not schedule long walks or long drives in the afternoon.
How to decide
Ask what your trip depends on. If it depends on a specific road, a specific park or a specific tour, check whether it operates in your dates before you book anything. If it depends on being somewhere warm with water nearby, the wet season may suit you better than the dry.
The cheap price is information, not a recommendation.
Check whether the road or the park operates in your dates before anything is booked, then price the trip through campervan hire in Australia once the dates survive that test.
Questions this raises
Is it unsafe to travel in the wet season?
Not inherently. The risks are heat, flooded roads and remote areas with limited access. Those are manageable with planning and unwise to ignore.
Do prices really drop in the wet?
Often, in the north, because demand falls. Whether that discount survives the loss of access depends entirely on your itinerary.