We are considering renting a campervan to travel for 2 months from Cairns to Sydney, starting in Cairns in September and ending in Sydney in November. We will rent a 2/3 berth HiAce or similar that only has air condition in the cab. We are concerned that the temperature may be too hot in the night and we won't be able to sleep. Can anyone offer advice please?
Well, this really depends on how well you sleep at night... it's going to be getting towards summer at that time of year. It doesn't stay hot all night, but it'd still be around 20 at night most of the time I'd say. I don't mind that, but like I said, some can't stand it!!
Yes, the temperature will be quite stable for you through this period because you are heading South. I would not be too concerned, the wet (humid) season kicks in Nov - Dec onwards in Qld. But for you, it should be quite nice. It also depends on what you class as hot!. We found sleeping with the windows open to catch any breese was helpful. I suggest enjoy your travels as the weather will not be too great an issue.
I would suggest to get some fly wire screen (ones to fit the car doors are readily available) also get some flyscreen an make some up for the other sliding windows so you still have some privacy & stop flying insects from getting in. Ruberised strip magnets will hold them on very well. Have a great time in Oz...