Average annual and monthly rainfall

What do the maps show?

These maps show the average annual and average 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 monthly rainfall is calculated by adding 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.

Further information

• About the maps - metadata and related information.
• Find out how climate statistics are calculated.
• Information about the range of gridded climate data we can provide.
• Other data available from the Bureau of Meteorology.
• Learn about the influences on the Australian climate.
• Explore other topics relating to climate education.
• Compare the average rainfall maps with recent rainfall.