About rainfall percentile maps

How were the maps created?

Rainfall data are recorded at a network of weather stations across Australia. The data from these weather stations are stored electronically in the Bureau of Meteorology's database called ADAM (Australian Data Archive for Meteorology).

The average rainfall percentile maps were based on daily rainfall data from about 16800 weather stations. The daily data were extracted from ADAM and a number of quality control checks were then applied to the data. For example, the data were checked for missing values over the length of the data record.

After the quality checks were applied to the data, monthly, seasonal, multi-seasonal and annual percentiles were calculated for each of the weather stations. An objective analysis technique was then applied to these station averages to produce regular gridded datasets (monthly, seasonal, multi-seasonal and annual) covering Australia.

Finally, the gridded data were visualised in a geographic information system and the colour maps created through this process.

Stations used in the analysis

Daily rainfall data from about 16800 weather stations across Australia were used to create the monthly, seasonal, multi-seasonal & annual rainfall percentile maps. These stations are shown in the map below.

recording stations used in the avrerage annual, monthly, seasonal and multi-seasonal rainfall percentile analysis

Rainfall percentile metadata

The following metadata summary, and detailed metadata file, provide information about the gridded rainfall percentile datasets. For example, information is provided about the format, spatial extents and analysis techniques used to generate the grids.

TITLE: Monthly, seasonal, multi-seasonal and annual rainfall percentiles (base climatological data sets)
DESCRIPTION: Monthly seasonal, multi-seasonal and annual rainfall percentile grids. The grids show the rainfall percentile values across Australia in the form of a two-dimensional array. The data are based on the period 1900–2019.
CUSTODIAN: Bureau of Meteorology
AVAILABLE FORMAT TYPE(S): ASCII row major, NetCDF, Shapefiles (upon request)
SCALE/RESOLUTION 0.05°/5 km; 0.01°/1 km (upon request)