1. The National Average: A Surprising Figure Australia is the world’s driest inhabited continent (after Antarctica). The average annual rainfall across the Australian continent is approximately 470 mm (18.5 inches) .

The national average is a — not a simple arithmetic mean of stations — to avoid over-representing denser coastal networks. 9. Summary Table: Key Rainfall Stats | Metric | Value | |--------|-------| | National average annual rainfall | 470 mm (18.5 in) | | Highest regional average | West Coast TAS: 2,400 mm (94 in) | | Lowest regional average | Lake Eyre (SA): ~120 mm (4.7 in) | | Wettest capital city | Darwin: 1,727 mm (68 in) | | Driest capital city | Adelaide: 543 mm (21.4 in) | | Rainfall variability (coefficient of variation) | >30% for most of continent; >100% in interior | | Average number of rainy days (national) | 50–100 days/year (varies from 5 in deserts to 250 in TAS) | 10. Conclusion: Living with the Average Australia’s average rainfall of ~470 mm conceals one of the world’s most extreme hydrological landscapes. From the monsoonal tropics to the Mediterranean south and the arid red center, the continent forces its inhabitants — human, animal, and vegetable — to adapt to boom-or-bust cycles. Understanding regional averages, seasonal drivers, and long-term trends is not an academic exercise: it is essential for farming, water management, bushfire preparedness, and flood resilience in a country where the “average” is often just a pause between droughts and deluges. Data sources: Australian Bureau of Meteorology (Climatological Atlas, 2024 update), CSIRO State of the Climate 2024, IPCC AR6 (2023).