Module 06 · Regional system
Regional rainfall across Australia
Annual totals tell only half the story. The timing of rain — even, summer-dominant, winter-dominant or monsoonal — decides how a tank fills and how long it must carry a household between rains.
Mean annual rainfall by capital
Rounded long-term averages. Nearly a threefold spread from Adelaide to Darwin.
Select a region
Choose a capital to see its rainfall pattern, seasonal distribution and what it implies for storage.
Seasonal bars are relative within each city, not comparable between cities. Figures are educational approximations of long-term averages.
Reading rainfall for storage
Two cities with similar annual totals can demand very different storage. Even rainfall — Hobart, Melbourne, Sydney — lets a smaller tank work hard, because it refills often and rarely faces a long dry gap. Concentrated rainfall — monsoonal Darwin, Mediterranean Perth and Adelaide — asks more of storage: the tank must capture a short wet season and ration it across a long dry one.
Evaporation adds a quiet third factor. Hot, dry climates lose stored and surface water faster, so cool Hobart stretches a modest total further than its rainfall alone suggests. The capture estimator lets you combine roof area with a rainfall level and watch the seasonal and overflow behaviour shift.