Worldwide, flooding is a common environmental hazard, and is also one of the major natural hazards that can cause death and economic losses in Australia. Flooding is the overflow of water onto normally dry land and is often caused by a prolonged period of rainfall, high-intensity/short-duration storms, or storm surges associated with tropical cyclones or other intense low pressure systems. Climate and weather, land-use, and social processes all have an influence on the occurrence of floods and their impacts. In particular, urbanisation, with a noticeable increase in impervious area, is a significant cause of increased flood volume and peak discharge. The magnitude and frequency of occurrence of floods as impacted by global warming and land-use change have been previously investigated. General Circulation Models (GCMs) have been used to derive climate projections. The uncertainty with climate projections based on GCM outputs is usually a concern, whereas examination and analysis of historical long-term rainfall data can provide an improved understanding of past climate change and help develop likely future climate change scenarios. The majority of research so far has examined changes in annual, seasonal, monthly, and daily rainfall. However, to date only limited work has considered the changes in sub-daily rainfall intensities in south-eastern Australia.