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The Bortle rating of a sky in a dark location varies with sky transparency. I have very little light pollution on my property located within the triangle between Young, Grenfell and Cowra. When looking for a place, I didn't even want to be in a small rural town. I wanted a rural setting without having to manage weeds, fire over 20-100acres. It took some looking but I eventually found a 3/4 acre property, subdivided from farmland. There are just 6 houses in a 1km x 300m strip. I am on the end with 100 acres of grazing land on one side and at the back.
I can see tiny glows on the horizon from Cowra and Young and a glow from a large mine near Galong. I can also see a longer faint glow along the horizon to the east from Newcastle Sydney, & the Gong. But these are all on the horizons where I wouldn't normally be observing anyway.
The Bortle rating varies from 1 on the clearest most transparent nights to around a 3 or 4 at certain times of year, when the sky is full of crop pollen, or dust, and even worse when there is fire smoke in the air. On the best nights, I have seen the LMC outer arm spanning 6-7 degrees in total with the naked eye. Recently, new neighbours 50m away installed a lot of outdoor lighting after moving in. They have however, been quite cooperative about not leaving lights on unnecessarily. Friends with observatories around Murrumbateman and Yass bring their scopes out here for the really dark skies.
I have looked back at light pollution maps from 2012 to present and though light pollution is increasing slightly in the closest towns, their growth is not in my direction. Rather, land is being developed away from me. I expect to have to leave this property due to aging out rather than being forced out by light pollution.
For comparison, those who have been to Qld Astrofest (Duckadang) or SPSP at Wiruna, the skies are much worse from permanent light pollution from nearby cities. These event locations need to strike a compromise where the distance from the city provides a reasonably dark sky and convenient access to the cities that provide the majority of participants.
Joe
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