The nature of precipitation as a highly variable intermittent phenomenon is discussed in the context of climate change specific to the location of the British Isles. The typical focus of precipitation studies on the amount within a specified time period is rejected in favour of a study examining the duration of wet and dry spells within the time series. The probability distribution of dry spells is well approximated by a stretched exponential distribution with no apparent scale break, suggestive of a single mechanism determining spell duration. A stochastic model based on the physical understanding of blocking anticyclones is presented.