Spring can be a great time to visit Australia as temperatures are warm but generally not very hot in most places (except the tropical north), and rainfall is low.
Southern cities like Sydney, Perth, Melbourne, and Adelaide are warm but generally not too hot, so conditions are ideal for city sightseeing. Sydney and Perth see October highs of around 71° F (22° C), Melbourne 68° F (20° C), and Adelaide 70° F (21° C). All of these cities have great beaches nearby, and although it'll probably be too cool to swim in October, that doesn't have to stop you from enjoying walks on the beach.
Temperatures in the tropical north climb in October, but they tend to stay steadier throughout the year anyway. Darwin sees October highs of around 91° F (33° C), and Townsville 84° F (29° C).
Daytime temperatures can also get pretty high in the outback by October, with highs in Alice Springs reaching 88° F (31° C). But, overnight lows are a cooler 59° F (15° C), so you'll still need a light sweater.
Rainfall is low in October almost everywhere. Brisbane and southern Queensland might be a bit wet, and the tropical north sees slightly more rain than it does between June and September, but in neither place is rain likely to spoil your plans.
Crowds and Costs
October is shoulder season throughout Australia. It's the tail end of the peak season in the tropical north, because although weather conditions are still generally good, October marks the re-arrival of deadly jellyfish in the seas, making it dangerous to swim. Southern parts of the country, especially the big cities, as well as Uluru and Alice Springs always get visitors, but you shouldn't expect huge crowds or high prices in October (or, higher than normal prices that is—Australia is always an expensive destination).
Where to Go
October is a good time to visit practically anywhere in Australia, although where you go will largely depend on the kinds of experiences you want to have, and your weather preferences.
If October is the only time you can travel to Australia and you want to experience the outback, you can do this in October even though it's not prime tourist season. Temperatures are always high here, but rainfall is relatively low. The Northern Territory is a good option, as there are attractions like Uluru, Kata Tjuta, Kings Canyon, and the national parks further north, like Kakadu and Litchfield.
October is a good time to visit southern Queensland and northern New South Wales, places like Brisbane, the Gold Coast, and Byron Bay. Conditions may be too cool to swim (depending on your preferences!) but temperatures are warm without too much of the stifling humidity that Brisbane is known for in the summer.
Sydney, Melbourne, Perth, Adelaide, Brisbane, and Canberra are great destinations year-round for lovers of art galleries, museums, restaurants, and other indoor activities. October is a good time to visit the cities because if you experience cooler temperatures you can retreat inside, but the weather should be good enough for walking around, too.
What to Do
If you really want to ski, head to the ski fields of Tasmania, New South Wales, Victoria, and the Australian Capital Territory as early in the month as you can and you may still find some snow. Ski fields tend to close by mid-October.
October isn't the best month sea swimming or water activities in Australia: temperatures will usually be too cold still in the south (unless you wear a wetsuit), and deadly stinging jellyfish return to warmer waters further north. If you want to swim outdoors, stick to hotels with pools in the north, or developments such as the Waterfront Precinct in Darwin, designed so you can cool off safely.
October is a good time for short or long-distance road trips in Australia, with pleasant temperatures and generally clear skies for nice views. Great shorter trips include the Great Ocean Road in Victoria and parts of the coast of New South Wales. Much longer options are also possible, such as Adelaide to Perth, Adelaide to Uluru or all the way to Darwin, and Brisbane to Cairns. Just make sure you have plenty of emergency supplies, especially when road-tripping through the outback.
Although Australia's winter doesn't get too cold in most places (relatively speaking), Australians tend to think it does, so spring is a time of celebration. There are many arts, culture, and flower-related festivals throughout the country in October.
Floriade. This Canberra festival is one of Australia's largest flower shows, and usually runs from mid-September to mid-October.
Film festivals. Film lovers should swing by Melbourne, Byron Bay, and/or Adelaide, as each city holds their film festival in October. The Melbourne International Film Festival is one of the oldest such festivals in the world. The Adelaide Film Festival is held every second year. The Byron Bay International Film Festival is another reason to visit the gorgeous northern New South Wales seaside town.
Traveling to Australia in October? Check out these great itineraries
Australia: Sydney, Cairns, and the Outback - 7 Days. Spend a week in three of Australia’s most eventful and beautiful regions—Sydney, Uluru, and Cairns.
West Coral Coast: From Exmouth to Perth - 7 Days. On this week-long journey through Australia’s West Coral Coast, adventure through the beaches of Exmouth and then to the capital of Western Australia—Perth.