Australia — the only continent wholly in the Southern Hemisphere — spans a vast latitudinal and longitudinal range.
Northernmost: Cape York Peninsula, Queensland — 10°39′S (10.65°S)
Southernmost (mainland): South Point, Wilsons Promontory, Victoria — 39°08′S (39.13°S)
Southernmost (including Tasmania): South Point, Tasmania — 43°39′S (43.65°S)
Span: ~33° of latitude (~3,680 km / 2,290 mi)
Westernmost: Steep Point, Western Australia — 113°09′E (113.15°E)
Easternmost: Cape Byron, New South Wales — 153°39′E (153.65°E)
Span: ~40.5° of longitude (~3,400 km / 2,110 mi at 30°S)
Coordinates vary slightly by dataset (Geoscience Australia, IHO, UN). Above uses GA's 1:1M topographic data. For legal/treaty purposes, use Australian Maritime Boundaries (AMB) dataset.
Australia: wide, flat, south, and entirely its own hemisphere.