Property insurance covers policyholders against losses arising out of a wide range of occurrences. Premiums are calculated by taking into account estimates of the frequency and the severity of the losses. Estimating the frequency and severity arising from claims caused by natural catastrophes is difficult, due to the relatively low frequency of natural catastrophes, and the unavailability of historical catastrophe claims data. The accumulation of a large number of claims in the geographical area affected by the catastrophe is of particular interest to insurers and reinsurers alike. This dissertation discusses the fundamental issues underlying the modelling insurance losses from natural catastrophes in South Africa. A suggestion is given of the key parameters that need to be taken into account, and a framework is given for models describing losses arising from floods, hail and tornadoes. Copyright / Dissertation (MCom)--University of Pretoria, 2003. / Insurance and Actuarial Science / unrestricted