Abstract: This paper describes two methods for generating synthetic rain rate time-series capable of being used to simulate the performance of radio communication systems operating above 10 GHz. Rain rates are modelled because they are widely available and because an approximate link to signal attenuation can be established owing to the significant correlation between them. The proposed models are based on hierarchic Markov chains. Rain and no rain events are simulated by the outer chain which simulates the rain event duration on the basis of the experimental statistics. The inner chain of both models deals with the rain intensity generation. The models therefore produce simulated rain samples whose statistics very closely match those of the experimental data without using any stored rain time series.