IFD and Preburst Rainfall for Australia

Enter a location in Australia to get its IFD design rainfall depths and the regional preburst and postburst rainfall depths and durations for that location. All data is free to use. The IFD grids are described in the IFD methodology report and the preburst and postburst statistics in the FMA 2026 paper.

What you get

IFD design rainfall depths

Intensity–frequency–duration (IFD) rainfall depths in mm for 25 durations from 5 minutes to 7 days and 13 annual exceedance probabilities (AEPs) from 63.2% to 0.05% (1 in 2,000), at any point on the Australian mainland or Tasmania. They are built from Bureau of Meteorology daily and sub-daily rain gauge records to June 2026, and compared with the BoM 2016 IFDs used in ARR 2019 and with the LIMB and HARC studies in South East Queensland in the IFD methodology report. Tables can be copied or downloaded as CSV.

Preburst and postburst rainfall

Preburst rainfall is the rain that falls before the design burst; postburst rainfall falls after it. Both matter for complete storm modelling and for initial losses. For the temporal pattern region of the selected location, the tool gives preburst and postburst depth, duration, intensity and ratio tables by burst duration and AEP, including sub-hour bursts not covered by existing ARR products. They come from a national complete storm database, described in the FMA 2026 paper.

Download IFD grids

Full Australian IFD grids as GeoTIFFs, one file per duration from 5 min to 168 hr. 1 km cells in GDA94 / Australian Albers (EPSG:3577), with one band per AEP (63.21%, 50%, 39.35%, 20%, 18.13%, 10%, 5%, 2%, 1%, 0.5%, 0.2%, 0.1%, 0.05%). Depths are in mm. The method and its validation are documented in the IFD methodology report.