With a land mass similar to that of the United States of America, winter snowfields larger than those of Switzerland, and with viticulture in every state, one-line descriptions of the Australian climate are hazardous. For all that, there are two basic weather patterns, one affecting Western Australia, South Australia, Victoria, and Tasmania (the southern states), the other governing Queensland and New South Wales.
The southern states experience a winter–spring rainfall pattern, with a dry summer and early autumn. Ridges of high pressure sweep across the southern half of the continent from Perth to Melbourne during the vines’ growing season, uninterrupted by mountain ranges; daytime temperatures typically range between 25 °C/77 °F and 35 °C/95 °F.