A simple Markov chain has been demonstrated to be a potentially useful device for making estimates of the frequencies and durations, from several hours to several weeks, of a large variety of weather events. In order to answer the practical questions, it was found necessary to simulate probability distributions by a Monte Carlo exercise. The resulting eight sets of charts have wide applicability. Abstract A simple Markov chain has been demonstrated to be a potentially useful device for making estimates of the frequencies and durations, from several hours to several weeks, of a large variety of weather events. In order to answer the practical questions, it was found necessary to simulate probability distributions by a Monte Carlo exercise. The resulting eight sets of charts have wide applicability.