Malaga and Costa del Sol are becoming more ‘tropical’ as nighttime lows no longer drop below 20C in summer

The average nighttime temperature in the Caribbean ranges approximately between 20C and 25C, according to meteorological data from that area. These same values were recorded in Malaga and the Costa del Sol almost every day during the summer months. In fact, in July and August, there were only two occasions when the thermometer fell below 20C and, on both occasions, it hovered just below at 19.7C and 19.8C.

It is precisely this threshold that defines the so-called “tropical nights” with, as can be seen, practically all of them occurring during the summer months, according to data from Spain’s Aemet state weather agency centre in Malaga, collected by the local weather forecaster José Luis Escudero.

Even worse: there have already been five nights during this time that were logged as “equatorial or torrid”, because the temperature did not drop below 25C. However, this year there has been no single “hellish night”, which is when temperatures reach or exceed 30C. That said, there was one day that came close: 20 July was the hottest night of the year, with 27.1C.

Warm sea

“Summertime minimum temperatures no longer drop below 20 degrees,” confirmed Jesús Riesco, head of Aemet’s Malaga weather centre. As for the causes, in addition to the consequences of climate change, the key lies in seawater temperature, as the minimum temperatures along the Costa del Sol coast are directly related to this factor.

“This year in June, the sea was very warm and the temperature remained high; therefore, the minimum temperatures didn’t drop on the coast, but in many parts of Andalucía they didn’t drop at night either, as is the case in the Guadalquivir Valley.”

This situation is increasingly distancing the province from the traditional Mediterranean climate, bringing it closer to others, such as the aforementioned Central American climate. Not only that, but also: “In June, July and August, practically all nights were tropical, above 20C, and there were increasingly more equatorial ones.”

Just look at the seawater temperature in the Mediterranean. “In our area, it varies a lot depending on the westerly (poniente) and easterly (levante) winds, but if we look at Almeria and the sea around the Balearics, there we can see that it is becoming tropicalised.” Water temperatures are approaching 30C.

However, Riesco goes on to point out that there are important differences with other climates around the world and that these high values occur primarily at the sea’s surface, unlike tropical seas that have a deeper layer with equally warm temperatures. Furthermore, the fundamental difference is that, in other latitudes, this situation persists year-round, while here, for the time being, it only occurs midsummer.

Additional energy costs

Enrique Salvo, chair for the climate change group at the University of Malaga (UMA), draws attention to the fact that minimum temperatures this summer have been even higher in Malaga city centre, according to the thermometer located at the port. “We are moving towards a strong tropicalisation, which entails additional costs in every respect and the first of those is electricity consumption,” said the researcher.

Added to this is the wear and tear that heat causes to humans, animals and plants, due to what is known as “biological fatigue”. Not surprisingly, mortality is increasing too, especially among the elderly and people with underlying health conditions. Another serious problem is the warming of the land, which no longer provides the nocturnal cooling it used to, with the exception of the few episodes of taró (sea fog), such as the one that occurred last weekend.

“This year we have had hardly any cooling from the sea and this leads to tropical night-time conditions that are tremendously draining for all living organisms. This has an impact on human functioning because we don’t get the same amount of rest and also due to the side effects of air-conditioning in terms of the development of respiratory diseases.”

More heat in the heart of the city

José Luis Escudero, a Malaga-based meteorologist, best known for his SUR blog Tormentas y Rayos (Storms and Lightning), gives a first-hand account of the change in nighttime temperatures experienced in Malaga city over the last half-century. “When I was ten years old, I used to go to the summer [open-air] cinema with my parents and I remember they always told me to take a cover-up… It used to get cooler at night on a regular basis and, in fact, the average minimum temperature has risen the most since 1974.”

This local weather expert focuses on the very high minimum temperatures recorded by the port thermometer, which reflects the situation in the city centre, both because of the effect of the so-called “urban heat island” and because the seawater has been very warm. In fact, in June, it set an all-time record for that month, reaching 25.7C.

For comparison, in July, the average minimum temperature in the port area was 23.3C, while that of the airport was lower at 22.6C. “The nights are warmer in the centre than in the outskirts”, said Escudero. Similarly, in August, the average night-time temperature at the airport’s terminals was 22.9C, while in the port it was 23.8C, almost one degree warmer.