Summer has lengthened. This is confirmed by a study by the Polytechnic University of Catalonia (UPC) which ensures that we have gone from having 90 to 145 summer days in the last 50 years. Likewise, daytime heat waves have multiplied by almost seven and nighttime ones by eleven in recent decades.
The research, which focused on analyzing warming in the main Spanish urban areas from 1971 to 2022, has been prepared by the UPC's Center for Land Policy and Valuations (CPSV) and was presented this Tuesday at the general assembly of the European Geoscience Union (EGU), in Vienna.
The cities that have formed part of the study are: Barcelona, Madrid, Valencia, Zaragoza, Seville, Malaga, Bilbao, Valladolid, Ciudad Real, Badajoz, Asturias, A Coruña, Ourense, Murcia, Logroño, Palma, Las Palmas de Gran Canaria and Santa Cruz of Tenerife.
The study confirms an average increase in temperatures in the main cities of the country. The maximums have risen by 3.54 °C and the minimums by 2.73 °C.
The results of the research show how climate change is also affecting Spain. In the main cities of the country, temperatures have risen by 3.54 degrees between 1971 and 2022. In addition, warm days have increased in two months and tropical nights have increased, from an average of 45 to 63 since 1971 .
The research recalls that the year 2022 was the warmest on record in many countries in southwestern Europe, and the second warmest in the rest of the continent with an average of 0.9 degrees more than the previous ones. According to the academics, the largest temperature anomalies took place in northeastern Scandinavia and in countries bordering the northwestern Mediterranean Sea.
Similarly, the average temperature of the Mediterranean increased more than the global average, which would explain the rise in temperatures in Spain.
The report, which highlights the danger to health posed by heat waves, recalls that in the summer of 2022 there were 22,249 additional deaths in Spain compared to the expected mortality, of which at least 4,732 were due to high temperatures.
The same study has also investigated the diurnal heat waves (Diurnal HeatWaves, DHW) and nocturnal heat waves (Night HeatWaves, NHW) registered in the studied cities. They consider a heat wave when there are three or more days with temperatures above the 95% percentile for the months of July and August, and have found that the increase in daytime and nighttime heat waves is constant.
Daytime heat waves have gone from three, as an annual average in the set of stations studied in the decade 1971-1980, and have been increasing progressively until reaching 21.9 in the decade 2013-2022. In the same way, nocturnal heat waves have also increased considerably, from 2.7 in the 1971-1980s to 30 in the 2013-2022 decade.
