Climate extremes are abnormal condition that occurs very rarely. They usually consist of large deviations from the mean condition, which, as such, have negative (if not disastrous) effects on ecosystems, land use and human activities.

The analysis of climate and its future evolution includes the description of intensity and characteristics of extreme events. The analysis of climate extremes is intrinsically difficult because of their low frequency and difficulty to reproduce them adequately in climate models. Typically for the evaluation of the extremes , models need to have a high space-time resolution and to reproduce the non-linear processes and the superposition of several factors that determine them. The statistics of extremes is a specific branch of the statistics, which uses a well-established mathematical theory that describes the likelihood of their occurrence. However, the difficulty of applying this approach has produced many studies that avoid extremes in the strict sense, but are limited to abnormal events, which are still sufficiently frequent to be described with sufficient reliability by models and detected by observations. Examples of climate extremes are heat waves, droughts, stormy periods, and in general an anomaly frequency of extreme weather events . In particular, the research activity of the laboratory has recently focused on extremes of the waves and the sea level.