Spain braces for third heatwave of summer as Aemet warns of 45°C highs from Tuesday

Spain's state meteorological agency Aemet confirmed on Saturday that a new heatwave, the third of the summer, will begin on Tuesday 21 July and last at least until Thursday 23 July. Temperatures are forecast to reach 45°C in some areas, with the southeastern third of the peninsula, the Guadalquivir and Ebro valleys, and the interior of Mallorca among the worst affected. The episode follows earlier heatwaves from 21–24 June and 5–9 July.

Forecast timeline and peak temperatures

The heatwave will bring a progressive rise in temperatures starting this weekend. On Saturday, inland Andalusia could already exceed 40°C. Sunday will see the most significant increases in the northern third and eastern half of the peninsula, with 40°C possible in the southeast. Monday, though not yet officially part of the heatwave, will see 38–42°C in the Ebro valley, eastern Castilla-La Mancha, and interior Mallorca, with up to 42°C in the southeastern interior. Aemet may later include Monday in the heatwave period if data confirm it.

Tuesday, the first official day, will bring widespread highs of 39–41°C in the Ebro valley, northeastern depressions, eastern Castilla-La Mancha, the upper and middle Guadalquivir valley, and interior Mallorca. The Genil basin could reach 42°C, and the southeastern third may locally exceed 44°C. Wednesday will see further rises in the southwestern quadrant, with similar values in the Ebro valley and Guadalquivir areas, while the southeast remains the most affected at 41–43°C, possibly 44°C. Thursday is expected to be the peak, with 42–44°C in the southeast, locally above 45°C, and 41–43°C in the Guadalquivir valley and Genil basin, and 40–42°C in the Ebro valley and northeastern depressions.

Meteorological drivers

Aemet attributes the episode to a reinforced blocking pattern, with a cut-off low (DANA) to the west of the Iberian Peninsula and an anticyclonic circulation over North Africa. This setup will push a mass of warm, dry air with suspended dust over much of the peninsula and the Balearic Islands. The agency noted that the blocking pattern, already causing very high temperatures in the eastern half of the peninsula, will strengthen over the weekend.

The blocking pattern, which is currently giving rise to very high temperatures in the eastern half of the peninsula, will strengthen again over the course of this weekend with the establishment of a DANA to the west of the Iberian Peninsula.

Health and safety warnings

Civil Protection has urged the public to limit sun exposure, especially during the central hours of the day, and to check on elderly people, those with illnesses, and those living alone. Recommendations include staying in well-ventilated places, eating light meals rich in water and mineral salts, drinking water frequently, wearing light-coloured clothing that covers as much skin as possible, and avoiding prolonged physical exercise in the hottest part of the day. Aemet warns of a significant danger level for vulnerable groups and outdoor activities, with very warm nights also expected.

Fire risk and environmental hazards

The heatwave will push the fire danger level to extreme values, accompanied by possible dry afternoon thunderstorms in mountain areas. Civil Protection has issued fire prevention advice, urging compliance with regional regulations on burning stubble, avoiding discarding cigarettes, rubbish, and glass bottles that can act as magnifying lenses, and not lighting fires or camping outside authorised zones. Negligence, the agency stressed, causes a large proportion of forest fires.

Climate change context

The current heatwave is part of a longer trend. Aemet data cited by El País show that between 1975 and 2000, only two heatwaves occurred in June in peninsular Spain; between 2000 and 2025, there were ten, a fivefold increase. Human-caused climate change is making these extreme episodes more frequent, intense, and severe, and they are arriving earlier in the summer.

While temperatures may begin to drop from Friday, Aemet cautions that uncertainty remains high and the heatwave could extend beyond Thursday.