Weather: Australasia/South Pacific

Water – or the lack of it – has everything to do with the weather across this vast realm where the Pacific and Indian Oceans meet. The island continent of Australia and its much smaller neighbours are surrounded by mammoth stretches of sea. If you took a globe and shifted it so New Zealand were at the top, all of the world's other big land areas (except Antarctica) would lie across the bottom half.

Given all the water lapping at its shore, it's ironic that Australia is the driest of the world's six settled continents. Most of the Australian coastline gets a healthy dose of rain each year, but inland it's a different story. There's no mountain range high enough to wring out moisture on the same scale as the Andes, the Rockies or the Alps. Moreover, Australia sits astride the 30° latitude band, where the world's great deserts cluster. All this leads to the infamously barren Outback, where you can drive for hours without seeing a single tree. Outback weather doesn't just occupy a piece of Australia – it dominates the vast bulk of it. More than 80 percent of the land area sees average highs above 33°C/91°F in mid-summer, although less than a million of the country's 20 million residents live in this zone. Sensibly, Australians prefer to congregate along the coast: near Perth, between Adelaide and Melbourne, and along the east coast from Sydney to Cairns.

Far to the southeast, New Zealand is a more authentic child of the Pacific. Like Japan, it's a set of mid-latitude islands that experience frequent day-today weather shifts from the westerlies encircling the globe. But while Japan is close enough to China for cold waves to blast through, yet far enough south for tropical heat to build in, New Zealand is insulated by its isolation. Its sheer distance from land areas, even from Australia, keeps things on the mild side. Average temperatures in Christchurch, on the South Island, are strikingly similar to London's (taking into account a six-month flip of the seasons, of course). The North Island is a touch warmer, but the main variations in New Zealand weather aren't so much north-to-south as east-to-west: rain and snow are far heavier on the western slopes than they are on the east. From New Zealand to the equator, the southwest Pacific is peppered with hundreds of islands that range from volcanic peaks to flat-as-a-pancake atolls. The weather across this zone is close to the quintessential tropical ideal, albeit a bit on the moist side. Tropical cyclones are a threat, although they're somewhat less common than across the northwest Pacific. Most of the rains are in the afternoon downpour category. Temperatures rarely dip below 18°C/64°F or rise above 32°C/90°F.