Why Tasmania's weather is so changeable, and what the westerlies bring
Tasmania sits squarely in the path of the Roaring Forties, the band of westerly winds that sweeps unbroken across the Southern Ocean from South America to our west coast. There is no land mass to slow them down, so by the time a front reaches Hobart it can swing the sky from blue to charcoal in under an hour. That is the origin of the local saying about four seasons in a day: a clear morning over the Derwent, a squall pushing in off Storm Bay by lunchtime, then sun again before dusk. The island's mountainous spine wrings most of the moisture out on the west coast, which is why Strahan is one of the wettest towns in the country and Hobart, in the rain shadow of kunanyi and the Central Highlands, is one of the driest capitals. For visitors and locals alike the rule is simple: dress in layers, carry a shell jacket, and never trust a single glance out the window.