Mmmm 4 months for a trip around Australia is realistically nowhere near enough time. We travelled for 12 months and dearly wished we could have had an extra 6 months so it didn't feel so rushed!

I think it is best to cover the Great Ocean Road from East to West. The rest I don't think it really matters which direction you go.

We based our start from Woollongong in January and timed things so that we would be in the Red Centre for the winter months - arriving around May/June if I recall. I know we were in Broome in July (heading south towards Perth).

We were very fortunate that year (1997) as we only experienced 6 days of rain for the entire time and the weather seemed perfect wherever we went.

With only 4 months I'd be inclined to take the August departure and just focus on exploring our Red Centre. Or a pocket of the country that particularly interests you.

Honestly, you could lose yourself for 4 months in any ONE state of Australia with no problems at all.

It just seems a little ambitious to me to be thinking you can travel around Australia comfortably in 4 months. I don't wish to be the wet blanket and am happy to offer further advice but it is something to consider.

Just saying!

I think the key consideration will be to avoid the north of the country during the Wet Season. I'd suggest starting in Sydney in mid winter (say mid July) then heading north. Maybe 4-6 weeks winding up the east coast, then from Cairns heading across the Gulf country to the Top End (Darwin Kakadu, Litchfield, Katherine, etc). Here you'd either head down the middle of the country to Alice, Uluru, Coober Pedy, the Flinders Ranges and Adelaide over the next 4-6 weeks; or continue SW through the Kimberley, down along the west coast to Perth, then east to Adelaide over 6 weeks. In either case, you'd aim to get to Adelaide by the middle of October. Then make your way via the Kangaroo Island, Great Ocean Rd, Grampians, Melbourne, Wilson promontory, Canberra, South Coast, etc to Sydney over your last month.

Are you coming to Western Australia?

If so, you'd do best to avoid Jan-March unless you like incredibly hot and often sticky weather.

April-May and Sept-November are excellent times to visit though. Sept-Nov will put you here during wildflower season, which is pretty spectacular.

I'd take the August start option and work your way south east. In August, the wildflowers starting in WA; FNQ is at its best; not too hot in Central Australia. Usually good weather, with the usual Spring vagaries of most countries, and warming up in the South. Tasmania is gorgeous at any time, but especially so in Spring & Autumn.

Looks like a great trip. Friends have just come back from 3 months moseying around parts of Queensland & Central Australia in a winnebago & loved it. They're locals, so have the luxury of taking their time and go away for 3 or 4 months each year.

In four months you can get a quick look at the eastern third of the country. An August start up the coast from Sydney would be good and then you could return south via an inland route. Southern Australia can be stinking hot in mid to late summer but it does not last long as a rule. The north east coast does not get particularly hot but the humidity knocks some people around. I strongly suggest that rather than relying on our opinions you check the climate data at www.bom.gov.au

How well do the two couples travel together? How similar are your interests? Have you worked out ways to give each other (as couples and individuals) a bit of space?

My mother and father-in-law (who are Australian) travelled around Oz in 4 months in a car with a tent. They are fairly active people - in their 60's - and found it a very busy 4 months! It is do-able but it will be hectic.

As for the best time to travel here - I am a Queenslander and it's hot from September through until April. We do get the the wet season in northern QLD but it can be beautiful - waterfalls are full and the landscape comes to life.

If you start in Sydney in August - I would probably travel north first & follow something like:
NSW & QLD - August
NT & top of WA - Septmber
WA & SA - October
VIC & Tas - November

That would have you finishing off our typically warmer months in a cooler part of Oz.

Happy Travels!

4 months.. you are so lucky. You will love Australia! I think everyone above has covered everything well.

Going right round Oz from Sydney, Grey Nomad wisdom seems to be to travel anticlockwise, to take advantage of the prevailing winds when coming back west to east across the Nularbor.

Personally, as an east coast Aussie, I hate February - too sticky and hot. The winter months would be much nicer. Today would be perfect for travelling, it's clear and sunny, though windy and cold. EllaViv's advice sounds good to me.

Thank you all for your advice. NOw starting to plan in ernest!

Just adding my tuppence worth. We visited Darwin down to Alice Springs in July / early August and had the most awesome warm weather - a gentle 28 degrees Celsius, low humidity. To me that would be the place to start, ending up in Sydney in October / November when the weather is warmer. I've been to Sydney in October 2011 and 2012 and the weather was mild at 19 - 22 degrees.

Season is really something to take in consideration when traveling to places. I have also read this on Travel Explosion as a family goes on a trip to Australia. Mostly are saying that you should avoid the wet season so you can enjoy your trip to the fullest.

With regards to the wet season it depends a bit on your attitude.

I love north Queensland in the wet and do get people coming here at that time of year because of the verdant nature of the nature. Birding can be more challenging in the rain but it does not rain all the time. On the other hand a lot of people melt in the rain. Tropical rain is not as cold and therefore does not make one as uncomfortable as getting wet in a cold climate.