Spain's fourth summer heatwave brings 42°C temperatures, extreme fire risk, and air quality warnings

Heatwave onset

Spain entered its fourth heatwave of the summer on Wednesday, with the State Meteorological Agency (Aemet) forecasting maximum temperatures of 42°C in several inland areas. The episode is expected to last at least until Sunday and could extend into early next week. Aemet has issued widespread warnings, placing nine autonomous communities under orange alert, the second-highest level, and four others under yellow alert.

Temperature extremes and alerts

The highest readings on Wednesday were forecast for Logroño, Pamplona, and Zaragoza, all expected to reach 42°C. In the river valleys of the southwest, the Ebro basin, and the northeastern depressions, temperatures were set to range between 40°C and 42°C. The northern plateau and La Mancha would see 37°C to 39°C, while the Canary Islands faced a sharp rise, with southern Gran Canaria surpassing 36°C. Orange alerts covered Andalusia, Aragon, Castile and León, Castile-La Mancha, Catalonia, Madrid, Navarre, the Basque Country, and La Rioja. Yellow warnings were active in Cantabria, Extremadura, Galicia, and the Valencian Community. On Thursday, a slight cooling was expected along the Cantabrian coast and the northwest, but temperatures elsewhere would remain largely unchanged or even rise slightly, with 11 communities still under alert.

Fire danger at extreme levels

The combination of high temperatures, southerly winds, and low relative humidity pushed the fire danger index to very high or extreme across most of the country, including the mountainous Canary Islands, Aemet warned. The winds, while not especially strong, were enough to complicate firefighting efforts at ongoing blazes in Madrid, Ávila, Toledo, and Castellón.

“Although the gusts will not be particularly intense, they will make it harder to extinguish the fires currently burning in the interior of the peninsula.”

Air quality concerns

A large mass of Saharan dust was forecast to reach the south and east of the Iberian Peninsula and the Canary Islands, combining with smoke and ash from the wildfires to degrade air quality. The Barcelona Dust Regional Center indicated that the dust event would persist through much of the week, with the highest concentrations in Catalonia expected from Thursday onward.

Health risks and duration

Aemet spokesperson Rubén del Campo cautioned that the heat posed a significant danger for outdoor activities during the central hours of the day and for vulnerable groups.

“This heat will be a major hazard for outdoor activities in the middle of the day and also a serious danger for vulnerable people, especially babies, the elderly, and those with pre-existing conditions.”

Minimum temperatures were also set to remain high, with tropical nights, not dropping below 20°C, forecast for the Mediterranean coast and the southern river valleys. The heatwave was expected to maintain its grip at least through Sunday, with the possibility of persisting into the following week. Isolated dry thunderstorms could form in mountain areas, though little to no precipitation was anticipated.