Alice Springs, Brisbane, Cairns, Darwin, Melbourne, Perth, Sydney
You can't look at a map of Australian rainfall and temperature without being struck by the effect of the Great Dividing Range. This low-slung set of peaks shelters the population belt of Australia's southeast coast from the dry, blastfurnace heat found through the vast interior. The Outback's well-deserved reputation for scorching summer heat is balanced by its invigorating winter, with sunny days ideal for bushwalking and nights that can chill below freezing almost anywhere. Great stretches of the Outback qualify as desert, but their low rainfall averages can be misleading, as long stretches of dry weather are punctuated by wayfaring tropical lows that drift across the country and produce rare bouts of substantial rain that can flood roads and strand people for days. Alice Springs, in the heart of the Outback, got 205mm/8.1in (close to its annual average) on a single day in March 1988.
On top of the Dividing Range is the nation's coolest climate outside Tasmania, with sublime summer weather and just enough snow to support a few ski resorts. Follow the range south across the Bass Strait to Tasmania, and the weather takes on a maritime cast, with coolness year round and rain or snow on more than half the days of the year. Australia's north coast is part of the great sweep of the Indian monsoon. Buckets of rain can fall, just as in southeast Asia, but virtually all of the rain arrives between December and April. After each summer's deluge comes a winter that's warm and humid but virtually free of rain from May to October.
The country's typical rainfall pattern is tweaked by two big influences: tropical cyclones and El Nino. Cyclones can sometimes linger for days and drop incredible amounts of rain in the north – more than 500mm/20in in a single day. El Nino tends to raise the odds for drought across the north and east, while La Nina makes flooding more likely. Drought has become more persistent across southern Australia in recent years, and climate-change projections show this trend continuing.
Victoria and New South Wales
Like a microcosm of the nation, this corner of Australia has a moist coastal climate on one side and a dry Outback on the other, with mountains in between. It's easy to see why Sydney and Melbourne were the first great cities to emerge down under. Along with their superb harbours, both have frequently magnificent weather. Winters are reliably cool but never frigid: it's seldom close to freezing in central Sydney (although snow fell in 1836), and near Melbourne, frost only rarely extends from the hills into town. In the Great Dividing Range, Canberra (at an elevation of 570m/1870ft) has typically frosty winter mornings and snow about once every other year, and above 1500m/4900ft the ground can stay white for several months each winter. As with much of Australia, the most dramatic extremes across the southeast tend to occur in summer rather than winter. That's when the sharpest contrast exists between a then-baking continent and an always-cool Southern Ocean. From spring through early autumn, thunderstorms often rumble eastward from the Dividing Range to the New South Wales coast from Sydney to Brisbane. They can bring torrential rain, frequent lightning, and occasionally large hail. Although it's cloudier and cooler than Sydney in the winter, Melbourne gets only half as much rain in a typical year, and it's more prone to blasts of summer heat escaping the interior. However, Sydney can simmer as well. In the great heat wave of January 1939, both cities hit all-time highs exceeding 45°C/113°F, while great stretches of the interior were ravaged by bush fires. This perennial threat can send a smoky pall to the coasts, destroying lives and property inland. Walkers should listen for warnings and avoid the bush during extremely hot and dry spells. Cool changes (cold fronts) sweep in from the south every few days during the summer, reducing the coastal temperature by as much as 20°C/36°F in an hour's time.
The split personality of the southeastern states extends to Queensland, but with a tropical tilt. Here, with the Dividing Range pushed even closer to the water, the contrast between the soggy coast and the parched interior is astonishing. In the wet season of 2000, Bellenden Ker (just south of Cairns) set a national rainfall record with 12,461mm/491in. Up and down the touristy stretch from Brisbane to Port Douglas, the mountains can wring rain out of southeasterly trade winds any time of year. The November-to-April “Wet” is by far the most likely time to produce travel-dampening deluges in which the rain doesn't stop for days on end, while August and September are the driest months. Townsville is a relative dry spot: the curve of its coastline reduces the impact of the trades, so only about 1000mm/39in of rain falls there each year. Tropical cyclones are a serious threat along the entire Queensland coast during the Wet; you're sure to hear if any big ones approach. None made landfall through the 1980s and 1990s, but Larry – the worst cyclone to hit Australia in decades – brought sustained winds of more than 185kph/115mph to the Innsfail area, just south of Cairns, in March 2006. Despite the severe damage wrought by Larry, there were no direct fatalities, a sign of increased awareness and pumped-up evacuation plans for the growing numbers of residents and tourists along the Queensland coast. Apart from cyclones, flooding can close roads any time during the Wet, especially in the far north. Most of Queensland, though, lies to the west of the mountains, from the ultra-tropical Cape York Peninsula to the parched Great Artesian Basin. The latter may experience widespread flooding without rain toward the end of a Wet, as rivers run off from the soaked mountains into the basin and toward Lake Eyre. Otherwise, western Queensland is much like the rest of the Outback: mostly dry year round, with summer heat and winter relief.
Acre for acre, this is the driest part of an already dry country. The bulk of South Australia gets less than 300mm/12in of annual rainfall. As in the rest of the Outback, ample water supplies are a must for travellers venturing north from the coastal hills and wineries into the desert. While it's not quite as hot on average here as in northwest Australia, most summer days soar above 30°C/86°F from Adelaide north, and readings above 35°C/95°F often envelop the whole state (Oodnadatta has topped 50°C/122°F). Winters are typically dry and cool across the desert; along the coast, they can be as cloudy and damp as in Melbourne, although the rain is usually a bit lighter. Perhaps the greatest weather-related spectacle is the moistening of Lake Eyre, in the state's northeast corner. Over 15 percent of Australia drains into this huge, usually dry salt pan. Every few years, often during La Nina, the lake partially fills. Waterfowl flock to the area, and brine shrimp and other sea creatures materialize.
There's a vast difference between the monsoon regime of Darwin and the classic desert climate of Alice Springs. Unlike the eastern states, this contrast is triggered not by a mountain range but purely by latitude. The northernmost quarter of the state – the Top End, which includes Kakadu National Park – is perpetually humid. High temperatures average 30°C/86°F or better year round, and the lows are only a few degrees cooler in winter than in summer. Most of the seasonal variation shows up in rainfall. The Top End shifts from insufferable heat during the monsoon build-up of October and November to near-daily thunderstorms in the summer, then to a bone-dry period from June to August when rain is virtually unheard of. Small, but intense, tropical cyclones can flay the coastline anytime during the Wet. Cyclone Tracy destroyed 70 percent of the buildings in Darwin on Christmas Day 1974, and Monica – the strongest cyclone on record to hit the Northern Territory – raked the state's north coast in April 2006. A gradual transition zone south of Darwin leads to the hot, dry regime that covers the state's southern half. Mid-summer nights at Uluru (Ayers Rock) typically hover above 21°C/70°F, and many afternoons top 38°C/100°F. The remnants of a cyclone or other low-pressure centre can bring a rare prolonged spell of rain to the Outback from summer into autumn. Fair-weather seekers will do best at Uluru from April to September, when each month averages only 1 or 2 wet days and daytime highs are typically close to room temperature.
If you want the most extreme weather Australia can dish out, this is a good place to start. Along the beautiful, but empty, northwest coast near the Hamersley Range, a single tropical cyclone can drift inland and halt a dry spell with a flood worthy of Noah. The town of Onslow has seen annual rainfall as low as 15mm/0.6 inches and as high as 1085mm/43in. Most of the nation's strongest tropical cyclones from 1950 to 2000 struck the Western Australia coast. With population and media outlets so scarce, travellers on the northwest coast during the Wet should watch for signs of impending cyclones and take heed. To the east, the Great Sandy Desert is Australia's hottest region, with an average high in January above 38°C/100°F; the town of Marble Bar hit this mark for 160 consecutive days during 1923–24. The southern half of the desert is a bit more tolerable. Cool changes sweep well inland from the west every week or so during the summer, and the immediate coast from Carnarvon south gets almost daily relief through medicinal sea breezes, such as the “Fremantle doctor” that graces Perth and the “Esperance doctor” that cools the Nullarbor coast to the southeast. When the doctor's absent, towns on the Nullarbor shore can jump from typical summer highs of around 26°C/79°F to readings above 45°C/113°F. The southwest strip from Perth to Cape Leeuwin is surprisingly Mediterranean, with toasty, dry summers and mild, soggy winters. It's damper here in July than anywhere else along the nation's south coast.
Peering at the rest of the continent from the poleward side of 40°S, Tasmania is a distinct region of its own in terms of weather as well as geography. Summer is the time to visit if you want conventionally nice weather, though even in January you should pack a jacket and raincoat. The mountains and west coast can get drenched any time of year. Hobart and other points to the east get lighter amounts, rarely pouring in the Sydney style – but even here, it's wet nearly every other day in summer and almost 2 out of 3 days in winter. There's nothing to block Tasmania's mountains from chilly upper-level winds, and snow can fall any time of year on short notice, so hikers should be well prepared. In winter, temperatures at sea-level Hobart never dip much below freezing, although snow falls across the elevated suburbs once or twice each year. Cool summer days are the norm in Hobart, though on very rare occasions a burst of heat pushes across the Bass Strait from Melbourne. After the air climbs and descends the island's peaks, it can send thermometers across southern Tasmania above 30°C/86°F on a few days each summer. In general, the air across Tasmania is uncommonly fresh, as the prevailing westerlies arrive along a continent-free path.