Barcelona, (EFE).- Summer days in the main Spanish cities have gone from 90 to 145 in the last 50 years, according to a study by the Polytechnic University of Catalonia (UPC), which confirms that daytime heat waves are they have multiplied almost by seven and the nocturnal ones almost by eleven in the last decades.
The study, prepared by the UPC’s Center for Land Policy and Valuations (CPSV), was presented today Tuesday at the general assembly of the European Geoscience Union (EGU), in Vienna (Austria).
According to the research, in the main cities of Spain the average increase in temperatures has risen 3.54 °C between 1971 and 2022, one of the most pronounced climatic anomalies in the world.
Tropical nights also increase
In addition to a two-month increase in warm days, tropical nights have increased by 18 and have gone from an average of 45 to 63 since 1971, according to the study, which recalls that 2022 was the second warmest year on record in Europe, with 0.9 °C more on average, and that in many southwestern European countries, it was the warmest year.
According to the researchers, the largest temperature anomalies occurred in north-east Scandinavia and in countries bordering the north-west of the Mediterranean Sea, although the average temperature of the Mediterranean has a greater increase than the global average and is a key factor in explaining the rising temperatures in Spain.
The UPC’s Center for Land Policy and Valuations (CPSV), linked to the Barcelona School of Architecture (ETSAB), has analyzed the warming process in the main Spanish urban areas from 1971 to 2022, analyzing data from 21 stations meteorological of all Spain.
Specifically, he has studied Barcelona (with data from the meteorological stations of the Fabra Observatory and the Prat airport), Madrid (Retiro park and airport), Valencia, Zaragoza, Seville, Malaga, Bilbao, Valladolid, Ciudad Real, Badajoz, Asturias, La Coruña, Ourense, Murcia, Logroño, Palma de Mallorca, Las Palmas de Gran Canaria and Santa Cruz de Tenerife.
health hazard
The study, 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 study concludes that the average increase in temperatures in the main cities of mainland Spain has risen 3.54 °C with respect to the maximum, 2.73 °C in the case of the minimum, and that the year 2022 has been the warmest year on record.
heat waves rage
The study also presents the diurnal heat waves (Diurnal HeatWaves, DHW) and night heat waves (Night HeatWaves, NHW) registered in the studied cities, considering a heat wave when there are three or more days with temperatures above the 95% percentile of the months of July and August, and has verified 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, to 9.4 in the period 1981-1990; to 8.8 in the 1991-2000 period; to 13.7 in the 2001-2010 period; to 15.8 in the 2011-2020 decade, and to 21.9 in the 2013-2022 decade.
As for the nocturnal heat waves, they have gone from 2.7 in the decade 1971-1980, to 6.8 (1981-1990); at 8.8 (1991-2000); at 20.7 (2001-2010); to 25.7 (2011-2020), and to 30 in the decade 2013-2022.