Time of year will be mid October - am hoping that is before the Wet arrives.
Rain can be unpredictable though, and when it rains up that way then unsealed roads and tracks can quickly become impassable.
I have been rained out twice in July in Central Australia. When it rains you need to get to blacktop quickly or you may get stuck.
The first time it started to bucket down and as we were just on graded tracks and not gravel we just headed for the Alice quickly. The morning after we arrived the Todd River was a raging torrent and we had to in the Alice wait 3 days for it to drop enough that they would allow us to cross it in our 4WD.
We had originally been going to head up the Birdsville Track. People were stuck on the Birdsville Track for weeks waiting for the ground to dry out enough to drive out.
At that time when we there, almost forty years ago, the road to Adelaide was not sealed, and the only road out of the Alice that was sealed was north! So while not part of our original plan, rather than cool our heels in the Alice where many things were closed due the weather we headed north to the amazing Mataranka Springs and Kathrine Gorge. Stopped enroute to view the Devil's Marbels. It was night and we viewed them in the glow of our headlights in pouring rain. The next day the sun came back out again.
As this is a flying forum the highlight of the gorge was that after having headed off on a series of boat trips down the gorge, and just after we were lying back relaxing and sunning ourselves after a swim, two Mirage RAAF jets appeared out of nowhere and screamed along the gorge, one actually flying in the canyon. The noise was amazing and the whole experience amazing and surreal.
On another trip we were when retracing the Burke and Wills Route from North to South we were visiting the Dig Tree on Cooper Creek. Arriving at the river crossing the water was a lot deeper that it usually is, but was not fast moving (With water crossings what makes them dangerous, or difficult, is the water velocity). I was a lot younger and more gungho back then and so even though we (my gf ,now wife, and I) were by ourselves in our Troop Carrier, I tarped up the engine bay, disconnected the fan belt and got the Tirfor (hand winch) out and ready just in case. The water went over the engine bay! We had started our trip by finding the northern most blaze tree from the expedition which is about 10km south of the Gulf of Carpentaria and so having already driven a fair old distance I did not want to miss this very important site on this particular trip.
All of which is a long post to say that while it is mostly dry up that way, that is unpredictable and you can't just go by the seasons.