Although we all know the term “heat wave” the truth is that we generally use and interpret it in a subjective way, which leads us to speak of this phenomenon imprecisely and based more on our impression of the heat than on scientific veracity.
It is normal to feel hot in summer. In Andalusia in general and in Seville in particular, maximum temperatures of over 35º or 38º are recorded in the summer period. But this does not mean that if one day temperatures are recorded above 40º we are facing a heat wave. Moreover, it should be borne in mind that the temperatures that determine a heat wave vary greatly between different regions and, of course, between countries.
A heat wave is not an extremely hot day. For this phenomenon to occur, we have to talk about several days of extreme temperatures that affect an important part of our geography.
The Spanish State Meteorological Agency (AEMET) establishes the following definition: “a ‘heat wave’ is considered to be an episode of at least three consecutive days in which at least 10% of the stations considered record maximum temperatures above the 95% percentile of their daily maximum temperature series for the months of July and August of the period 1971-2000″.