article_detail

 

Spain is bracing for a major heat wave this weekend, with temperatures expected to reach as high as 45ºC in parts of the country. From Friday June 27, the first prolonged, widespread heat wave of the summer will take hold, bringing scorching days and little relief at night.

 

The heat will begin to build from Thursday June 26, when a powerful ridge of high pressure settles over the entire country and a mass of hot, dry air from North Africa pushes temperatures far above seasonal norms.

 

 

By the weekend, almost the whole country, with the usual exception of the northwest and parts of the Cantabrian coast, will be feeling the heat.

 

Inland areas of Andalucía, Extremadura, Castilla-La Mancha, Aragón and Murcia are expected to experience the worst of the heat. In the Guadalquivir, Guadiana, Ebro and Tagus valleys, daytime temperatures could soar to 44ºC or higher on Sunday June 29 and Monday June 30.

 

 

Many regions, including inland Mallorca and the Júcar and Segura valleys, will see temperatures approaching or exceeding 38ºC.

 

In the north, the increase will be slower but still significant. In Castile and León, for instance, highs above 35ºC are expected from Sunday.

 

Unfortunately, we won’t get much of a break at night. Lows will remain uncomfortably high, especially in the southern half of the country, the Mediterranean coast and the Ebro Valley. In many areas, temperatures will not fall below 23ºC to 25ºC, bringing widespread tropical nights and, in some locations, even equatorial ones.

 

 

According to the State Meteorological Agency (Aemet), this sustained heat could last for more than five days, making sleep very difficult without the fans or air-con blasting.

 

Adding to this discomfort, a calima – that dreaded mass of suspended Saharan dust - is forecast to arrive from North Africa on Sunday. This will primarily affect the western half of Spain and may be accompanied by hazy skies. The dust could impact visibility and air quality, while also creating uncertainty around temperature forecasts for early July.

 

Although a slight drop in temperatures is expected from Wednesday July 2 in western areas, the heat will persist in the south. In parts of Andalucía and Extremadura, highs of 38ºC or more may continue well into next week.

 

 

In the Canary Islands, Saharan air will also raise temperatures, particularly on Friday June 27 and Saturday June 28. Gran Canaria is likely to see the worst of it, with highs of 35ºC to 37ºC in mid-altitude areas and on south-facing slopes. Some calima is also expected in the eastern islands, although the episode is not expected to reach heat wave intensity there.

 

 

A heat wave is not just a single hot day. It is defined as a prolonged period of abnormally high temperatures. In Spain, a heat wave is declared when at least 10% of weather stations register maximum temperatures above the 95th percentile of historical records for several consecutive days, typically in July and August.

 

While many heat waves are marked by dry, sunny weather, humidity can also play a role. It raises the ‘real-feel’ temperature and adds to the discomfort. However, too much moisture can lead to cloud formation, which may act as a shield and moderate the heat a bit.

 

Climate also plays a role. What qualifies as a heat wave in northern Spain might be considered normal in southern regions like Andalucía or Murcia, where summers are already intensely hot. In those areas, a heat wave can turn already stifling conditions into something much more extreme.

 

 

Images: Aemet