heatwave

A notable episode of heat, resulting from the advection of a very warm (tropical or subtropical) air mass over a vast expanse of territory, lasting at least three days, in some cases extending to several weeks. During the longest-lasting heatwaves, there are a series of ups and downs in the intensity of the heat. There is no single, universal definition of the criteria that must be met to classify a heat episode as a heatwave. Each National Meteorological Service establishes its own, based on exceeding certain thresholds. The maximum temperatures reached during the warmest months of the year are usually taken as a reference. In the current climate context - marked by global warming - heatwaves are no longer restricted to the summer months (June, July, and August), with some of them also occurring outside the summer period.