Spain's first summer heatwave pushes thermometers to 45°C, with Tuesday set as the peak before a Thursday cooldown

Peak intensity

This Tuesday is expected to be the most extreme day of the episode, with the highest values concentrated in the interior and along the Cantabrian coast. The state weather agency AEMET has issued orange and red warnings for large parts of the country. In the Basque Country, the interior of Vizcaya and Guipúzcoa will be under red alert, while the province of Toledo and Ciudad Real remain under orange warning with highs of 42°C that could climb higher in valleys. The Guadalquivir, Guadiana, Tagus and Ebro valleys will see the most persistent heat.

On Monday, the town of Andújar in Jaén recorded 45°C, while 42°C was reached in Navarre, Aragon and Catalonia and 41°C in the Basque Country. Jaén province had already registered a maximum of 44.8°C earlier in the episode. The meteorologist Roberto Brasero warned about the progression:

This Tuesday temperatures will rise even more in the west of the peninsula, especially on the western Cantabrian coast where the rise will be 6 or 7 degrees compared to yesterday. And a lighter rise in Extremadura and western Castile and León where they will add 2 or 3 more, but enough to, together with the rest of Spain which will hardly change, make tomorrow the peak of this heatwave.

Sleepless tropical nights

The heat is not retreating after sunset. Widespread tropical nights, with minima above 20°C, are forecast for most of the country, while coastal and urban areas in the south, east and eastern Cantabrian region will endure torrid nights above 25°C. Cities such as Madrid, Almería and Zaragoza may experience what meteorologists call an 'equatorial night', with thermometers staying above 25°C throughout the early hours.

Brasero noted the exceptional conditions for the traditional San Juan bonfires:

If we review the minimums forecast for tomorrow's early morning, we see very few capitals that can drop below 20°C (Teruel, Soria, A Coruña, Santander... with lows of 18 or 19 degrees) so in most of Spain the night of San Juan will be tropical or even torrid.

One cold spot in a scorching country

Amid the nationwide furnace, the small town of Salvacañete in Cuenca offered a rare reprieve. At an altitude of 1,200 metres and nestled in the Cabriel valley, the town woke up on Monday morning to 9.6°C, while most of the peninsula was already above 20°C. Its mountain microclimate keeps night-time lows between 11°C and 13°C this week, although daytime highs still reach 30–35°C.

Why the heat dome is so persistent

A blocking high-pressure system, often called a heat dome, is trapping a mass of very warm, dry Saharan air over the Iberian Peninsula. The air mass is being compressed and heated day after day without any fresh inflow. According to La Razón, values are running between 5°C and 10°C above normal for late June, with anomalies even larger in the northern half of the country.

Outlook and health advice

AEMET expects the episode to persist with high probability until Wednesday, when slight drops will begin on the Atlantic side. A more significant cooling will arrive on Thursday, bringing a marked end to the heatwave. Until then, the OCU (Organisation of Consumers and Users) recommends drinking around 2.5 litres of water daily, avoiding the outdoors between 12:00 and 17:00, and prioritising light, fresh meals. The agency also warns about heatstroke symptoms such as dizziness, red skin, headache, accelerated pulse and confusion, urging people to seek medical help if they appear.