Average annual and monthly days of rain maps

These "days of rain" maps show the average number of days, for each month and annually, when rainfall totals exceeded values ranging from 1mm to 25mm.

Product code: IDCJCM003

What do the maps show?

The days of rain map series shows the average number of days when rainfall exceeds the total specified in each month and annually. The average annual days of rain above a specified threshold is calculated by counting the number of days with a rainfall total above that threshold in each year (between 1961 and 1990). The total number of days for each year are then added together, and this value is divided by the number of years in the period (30 years in this case). Average monthly days of rain above a specified threshold are calculated in a similar manner.

These maps can be used to determine areas which have many days of rain (for example coastal Queensland) and which have few (for example central Australia). They can also be used to determine when heavy rainfall is most likely to occur. For example, Darwin has many days in January, February and March when more than 25mm could be expected to fall. This period is during the northern wet season (October to April) and the climate is influenced by the Australian monsoon.