The different effects of climate change do not affect all countries in the world equally. Spain is one of the countries where heat waves They are acting more intensely and more frequently. While in other countries heat waves typically last an average of 3 to 4 days, in Spain they last 4 to 5. To learn more about how these waves are documented, see heat waves in Spain.
A study has been carried out in which the Institute for Environmental Diagnosis and Water Studies of the Higher Council for Scientific Research (CSIC) and which has been published in the scientific journal Environmental Health Perspectives, which analyzed heat waves that occurred between 1972 and 2012 in the 18 countries where these extreme weather events are most common. What results did they obtain?
The study carried out has examined the temperature figures measured by the State Meteorological Agency of all the provincial capitals. As with droughts, there is no global definition of what a heat wave is. However, the study was based on the twelve concepts most agreed upon by the scientific community and research was also carried out on the impacts of heat waves.
According to the data obtained after all the registrations, the highest rate of heat waves is taken by Spain which, after China, lead the list of countries with the most heat waves since records began. Not only that, but the increase in the frequency and intensity of these extreme events has increased significantly since 2003. This trend is also related to the fact that Spain still does not face climate change.
This increase in heat waves was predicted by scientists as the consequences of climate change. As global warming increases, the effects of climate change are accentuated. In Spain there have been an average of 32 heat waves per year. To understand how these events occur, see how heat waves occur.
The area of Spain where these phenomena are most concentrated is the southern half of the Peninsula. The risk and death rate due to heat waves have also increased, highlighting the importance of understanding these phenomena. appropriate protective measures.
Spain, as we have mentioned many times, is a very vulnerable country to climate change, and scientific studies and records only confirm this. For details on these effects, you can read about global warming and its effects on heat waves.
Since 2015, Spain has experienced a significant increase in the frequency and magnitude of heat waves. According to the State Meteorological Agency (AEMET)Heat waves are episodes that must be considered based on several factors. To define a heat wave, AEMET has established that at least 10% of meteorological stations must exceed the 95th percentile of their historical maximum temperatures for three consecutive days, which is a criterion that has evolved over time. This has been reflected in how Heat waves put several provinces on alert.
To put this phenomenon into perspective, in the summer of 2023, Spain experienced seven heat waves: four in the Iberian Peninsula and the Balearic Islands, and three in the Canary Islands. These figures reflect an intense summer; however, if you look at it broadly and compare it with records from previous summers, these seven heat waves indicate a increasing trend in the frequency and intensity of these extreme weather events, which, as we already know, is a consequence of global warming.
In Seville, where approximately 60% of July and August days see highs above 35°C and 25% above 38°C, a high of 38°C will be a very hot day, but not hot enough to qualify as a heat wave. On the other hand, if this temperature occurs in Molina de Aragón, where 38°C is the absolute maximum temperature recorded, those 38°C temperatures could be part of a heat wave. For more details on the extreme temperature situation, see temperature records in the history of Spain.
To better understand this phenomenon, it is important to consider how heat waves impact public health. A study by the Carlos III Health Institute highlighted that heat waves could be responsible for a significant increase in mortality, especially among vulnerable groups such as the elderly and people with pre-existing conditions. These studies underline the need to apply appropriate prevention and protection measures, especially during heat peaks and you can learn more about the deadly heat waves that will become more frequent.
With this, and "after testing different thresholds", the definition chosen by Aemet To identify a heat wave is as follows: It is an episode of at least three consecutive days, in which at least 10% of the stations considered registered maximums above the 95% percentile of its series of daily maximum temperatures for the months of July and August during the period 1971-2000.
The Most Important Heat Waves in Spain
Regarding the criterion to define the intensity of a heat wave, the Aemet chooses four factors: The temperatures reached, their duration, the extension of territory affected and the wave anomaly, "it is necessary to quantify these aspects for each wave if we want to evaluate and compare them." To learn more about these criteria, you can visit the worst heat waves in Spain.
Once this work is done, Aemet issues its ranking. And until this summer ends and the 2024 data is published, These have been the most significant heat waves suffered by Spain (Peninsula and Balearic Islands) since records began in 1975.. In addition, we will also grant a Special prize to the worst heat wave in the Canary Islands, where the data is processed independently.
The Most Notable Heat Waves
4. The heat wave of August 8-11, 2012
With a duration of four daysIn August 2012, a heat wave affected 40 provinces, the second most extensive so farThe warmest day was August 10, with a maximum wave temperature of 39,5°C; and, although in this sense, this wave is surpassed by others in the ranking, in the other cases their territorial extension was smaller (a fact that also influences this).
According to Aemet, heat waves that reach higher maximum temperatures tend to be those that are smaller in area and affect warmer areas. In the case of this wave, however, As it extends across almost the entire Peninsula – with numerous stations in the northern half – the temperature obtained is moderated. For this reason, it is crucial to understand how Heat waves can also be unusual phenomena.
3. The heat wave from July 30 to August 14, 2003
With 16 days duration, this has been the third longest heat wave on record and has affected 38 provinces. As in the previous case, The wave anomaly was 3,7ºC. "Furthermore, the summer of 2003 was very hot overall, being the second warmest in the series so far, with a national average temperature of 23,6°C, after 2022, which had an average temperature of 24,0°C," explains Aemet. This year, like others, illustrates the growing trend of heat waves in Spain.
2. The heat wave from June 27 to July 22, 2015
The second most important heat wave identified by Aemet for the Peninsula and the Balearic Islands is that of the summer of 2015, which, with a duration of 26 days, It has been the longest heat wave on record. As for its extension, this heat wave reached up to 30 provinces.
The hottest day was July 6; on this day, temperatures exceeded 40°C across virtually the entire Peninsula—with the exception of the northwest—and reached 45,2°C at the Córdoba/Airport and Montoro stations, also in Córdoba. As for the maximum wave temperature, it was 37,6 °CThis event marks a key point in the history of heat waves in Spain, as it represents a clear example of what happens in an extreme summer, as has been observed in the driest summers in recent years.
1. The heat wave from July 9 to 26, 2022
And the first position goes to… The second heat wave of the summer of 2022! That wave happened between July 9 and 26 and had a 18-day duration (the second longest in the series). This, in addition, It was combined with a large extension and intensity: it has been the wave that has affected the most provinces (44) and also the most intense, with a wave anomaly of 4,5 °C.
«It is, therefore, the most extensive and intense heat wave and the second longest, given the circumstance that after a respite of only three days, on July 14 a new heat wave began that lasted until August XNUMX," presents the Aemet.
La The maximum temperature of the wave was 38,1 °C, recorded on July 14. That day, temperatures in both the central and southern parts of the Iberian Peninsula and parts of Catalonia, Castile and León, and Galicia exceeded 40°C; some stations in the valleys of the Tagus, Guadiana, and Guadalquivir rivers reached 45°C. Minimum temperatures were also very high. This heat wave reinforces the idea that the Climate change is also affecting biodiversity.
Special Award: The most important in the Canary Islands
In the Canary Islands it is somewhat more difficult to choose the most important heat wave, according to Aemet, "but we will choose the most notable one the one that occurred between August 5 and 15, 1976, lasting 11 days, with an anomaly of 6,1°C and the two provinces affected«.
Some records worth remembering
The heat has also left some records in Spain that are worth remembering. The highest temperature recorded in Spain to date is 47,6ºC, in La Rambla (Córdoba) on August 14, 2021.
Moreover, the hottest summer title –nationally and since records began in 1961– it was the summer out of 2022, which saw 41 days of heat waves. That same year, The second earliest heat wave; the first was on June 11, 1981, and lasted six days.
If data is considered at a global level, it is highlighted that, This week, the planet experienced the hottest day in recent history., according to preliminary data from the Copernicus Climate Change Service. As we reported in this article, the record was reached on July 21, 2024, with an average global temperature of 17,09°C. But it didn't end there: just one day later, this record was broken again, reaching 17,15°C.
A figure that serves as a culmination of a situation that has been occurring for some time: planet Earth has twelve consecutive months breaking temperature records for the corresponding month. Among them, the June was the hottest month on record, which adds pressure on heat waves in Spain and around the world.
In recent years, and according to reports from international organizations such as the World Meteorological Organization (WMO) and the Intergovernmental Panel on Climate Change (IPCC), The planet is warming at an unprecedented rate. In 2023, the global average temperature was approximately 1,4°C above the pre-industrial average.
This rise in global temperatures is being driven by the high concentrations of greenhouse gases (such as carbon dioxide and methane) in the atmosphere. This not only causes warming, but also increase in the intensity and frequency of extreme weather events – such as heat waves – globally. For more information on this, you can check out the fire risk map in Spain.
Between 1975 and 2000, there were seven years with more than one heat wave; but between 2001 and 2023, this number doubled, with 15 years with multiple heat waves. This demonstrates a clear trend in the climate, which can be seen in the increase in .
Spain, in particular, due to its geographical location and climatic characteristics, has experienced a significant increase in the frequency of extreme heat episodes., especially since the 70s. According to Aemet, Between 1975 and 2000, there were seven years with more than one heat wave; but between 2001 and 2023, this figure doubled, with 15 years of multiple heat waves recorded (and that's a slightly shorter period).
You may be feeling very hot as you read this; you may be bored of hearing about it, or you may be thinking, "I know it's hot, no need to tell me about it again!" But It is precisely this repetition that should raise alarm bells.: Combating climate change is urgent.
