Spain on alert for first heatwave of summer: temperatures to hit 42 °C, nights will stay above 20 °C
Aemet has issued a special warning for a 'very intense' and persistent heat episode that will push daytime temperatures to 40–42 °C across much of the peninsula and keep nighttime lows above 20 °C from Saturday.
Forecast triggers early warning
Spain’s State Meteorological Agency (Aemet) activated special notices on Wednesday as all models pointed to a prolonged episode of extreme heat that will start over the weekend and last at least until Tuesday. The combination of a Saharan air mass, a blocking ridge over Europe and a cut-off low to the west of the peninsula will drive temperatures 5 to 10 °C above normal, and locally up to 15 °C above the June average in the northern half of the country. Aemet spokesperson Rubén del Campo called the episode “very intense,” noting that the persistence and geographic breadth make it likely to be classified as the first official heatwave of meteorological summer 2026.
Given the high temperatures expected, the persistence of the episode and the affected geographic area, we are probably facing the first heatwave of this summer.
Day-by-day peak of the heat
Temperatures will already exceed 35 °C across much of the interior, the Ebro valley, the south-west and Mallorca on Wednesday, with values reaching 38 °C in the Guadalquivir and Ebro valleys. Thursday and Friday will see similar conditions, punctuated by afternoon storms with hail and strong wind gusts in Galicia, Castilla y León, the Cantabrian range and the Pyrenees.
Saturday marks the start of the sharpest rise. By Sunday the mercury will climb to 38–40 °C in the Ebro, Tajo, Guadiana and Guadalquivir valleys, with 42 °C possible locally in Córdoba or Badajoz. Monday is expected to be the hottest day: 39–40 °C will be widespread in all major river valleys, 38–40 °C across La Mancha and the south-east, and 36–38 °C on the northern plateau. On Mallorca, 34–36 °C are forecast. A slight cooling is possible from Tuesday 23 June, but temperatures will remain well above normal at least until mid-week.
- Temperatures already 35–38 °C in southern and central Spain; storms in the northwest.
- Thursday, 19 June: similar heat, afternoon storms in Galicia, Castilla y León and the Pyrenees.
- Saturday: temperatures begin sharp climb; 40 °C possible in scattered inland points.
- Sunday: 38–40 °C in the major river valleys, locally 42 °C in Córdoba and Badajoz.
- Monday: peak of the episode – 39–40 °C in valleys, up to 42 °C locally; tropical nights widespread.
- Tuesday: slight cooling likely, but temperatures remain well above normal into mid-week.
Persistent heat at night
Nighttime will offer little relief. Lows will stay above 20 °C across wide areas – the threshold for a tropical night – and in parts of the Mediterranean coast and the southern half will not drop below 25 °C.
In large parts of the peninsula the minimum temperature will not fall below 20 °C, and in Mediterranean and southern areas there will be places where it will not drop below 25 °C.
Wider climate context
The episode arrives after the second-warmest spring since records began in 1961, with a seasonal anomaly of +1.6 °C. The Minister for Ecological Transition, Sara Aagesen, pointed to data showing that the Mediterranean reached its highest water temperature since 1940 in 2025, with a basin-wide average of 20.1 °C around Spanish coasts. Spanish heatwaves have doubled in frequency compared with each of the previous decades since 1975 and are appearing increasingly early in the year.
Alerts and precautions
Heat warnings are active across the Ebro valley, Madrid, Andalusia and Extremadura, with 43 provincial capitals already above 30 °C. Authorities ask that people avoid sun exposure in the central hours of the day, stay hydrated, wear light clothing, and pay special attention to children, the elderly and vulnerable groups. The combination of dry storms and extreme heat will elevate wildfire risk, especially in the north.
