That's pretty consistent with most outback areas. I've travelled on holidays extensively out west in NSW, Qld northern SA, and you can go through for 20 years and it's just red dirt and stones, but on the 21st you can drive for days through waist high wild oats, and get bogged all day long at every depression. On one occasion we left the Flinders Ranges up the track to Maree. A couple of hours later a storm blew in and vehicles started getting bogged in the dips. We made it into Maree and spent thr night bogged in the main street. Three days later the roads were fit for travel.In the other trips we've made to Maree since the tracks around Maree over the years have been as hard as bitumen.
After rain airfields really need an on the ground inspection. I checked out the Booligal Pub airfield from the road and it looked perfectly smooth. From the pub it looked smoother. I decided to walk it anyway and it had big crab holes, some half a metre deep.
On one occasion a Hay Council worker told me he'd followed the grader out along a track to the north west with a water tanker they'd bought at an auction. It started raining before they'd finished their shift so they turned around and came back in the rain. The truck had a Detroit 6V53 and Allison transmission. As truckies would know that's about the last specification you'd take outside Sydney. "After a few minutes" he said "the truck started cutting two grooves in the wet road, the Allison changed down to low and I had to flat foot it all the way home, the screamking engine left me deaf and I had to take a bawling out for leaving 80 km of grooves in the road which had hardened like concrete a day or two later.
Despite the fast nature of a surface becoming unusable with rain in any district at any odd time, there are lots of times that the surface doesn't change for years, so the local fliers know what signals to watch for, but for cross-country fliers it's critical to get up to the day information because as OT said the airstrip isn't a priority when the locals know they won't be using it for months.