Spain’s State Meteorological Agency (AEMET) issued a warning last Friday over the arrival of the second heatwave of the summer of 2026, a spell that begins this Sunday and will bring temperatures of up to 42°C in the south-western river valleys of mainland Spain, lasting at least until Tuesday.
According to the agency’s own data, on Monday temperatures are expected to reach 38–40°C in the Miño valley and 37–39°C in inland A Coruña, while in the south-western quadrant maximums of 39–41°C will be widespread, rising to 42°C in river valleys, with 37–40°C on the southern plateau, in the Ebro valley and in the north-eastern depressions.
Contrary to what is often assumed, the peak of the episode will not come on Tuesday. According to AEMET, Monday 6 will be the harshest day of the period, with further temperature rises on the eastern Cantabrian coast that will spread to a lesser extent to the Ebro valley, the northern plateau and the eastern third of the peninsula, with temperatures possibly reaching 44°C on Tuesday which would complicate the Bisbal d'Empordà wildfire, while in western Galicia the arrival of maritime air will start to be felt, bringing temperatures down along the coast.
On Wednesday, with greater uncertainty because of the possible influence of a high-altitude cut-off low pressure system known as a 'dana', the most likely scenario points to values remaining above 39–40°C in the south-west, on the southern plateau, in the Ebro valley and in parts of the south-eastern interior, before temperatures begin to fall from Thursday onwards.
