These rainfall maps show the average annual, seasonal and monthly rainfall distribution across Australia.
Product Code: IDCJCM004
These maps show the average annual, seasonal and monthly rainfall over the period 1961 to 1990. Average annual rainfall is calculated by adding rainfall totals over a specified period (1961 to 1990) and dividing by the number of years in that period (30 years in this case). Similarly, average seasonal/monthly rainfall is calculated by adding seasonal/monthly rainfall totals and dividing by the number of years in the specified period.
The annual rainfall map shows that extensive areas in central Australia are generally very dry. Rainfall in these areas is highly variable and falls on very few days. These areas are under the dominance of the subtropical high pressure belt for most of the year, and lie far from potential moisture sources.
Rainfall generally increases towards the coast as proximity to both moisture sources and reliable rain-producing weather systems improves. Elevation also has an important influence on rainfall, with the mountain areas of northeastern Queensland, southeastern Australia and western Tasmania receiving higher rainfall totals.
In the northern parts of the country, most of the rainfall is associated with the monsoon and occurs in the summer months. In southern Australia, most rain falls during the winter months and is normally associated with frontal systems.
