Oz stretches around thousands of miles north to south, east to west. We have significant variance in climates. A lot of area in tropical zones, stretching down to temperate and cold (particularly in the east). In the high country, extensive snowing.

Tassie gets pretty seriously cold, I think.

So, in most highly populated areas, not as cold as massachusetts, I guess, but still, pretty cold. Also, Australia is over-urbanized. Far too many population live in urban areas where they cannot access other resources to heat their homes easily.

Here in Vic it can get down to 0 deg C overnight...also, our houses are built like bus shelters-not great insulation when it comes to cold. But we also get highs of over 40 deg C in summer so, a fair bit of variation. Can be 4 seasons in one day sometimes.