Rainfall is a highly non-linear hydrological process that exhibits wide variability over a broad range of time and space scales. The strongly irregular fluctuations of rain are difficult to capture instrumentally and to handle mathematically. The purpose of this work is to contribute to a better understanding of the variability of rainfall by investigating the multifractal behaviour that is present in the temporal structure of rainfall. This type of rainfall analysis is based on the invariance of properties across scales, and it takes into account the persistence of the variability of the process over a range of scales.