Spain set new benchmarks for extreme heat when June 22 and 23 were recorded as the hottest June days since at least 1950. Provisional data from the Agencia Estatal de Meteorología (AEMET) put the average temperature anomaly across the peninsula at 7.1°C above normal, surpassing the previous record set on June 30, 2025. The episode ran from June 20 to 27 and opened a summer marked by repeated, prolonged heat.
The impact extended beyond daytime highs. Nighttime temperatures on June 22 and 23 were the warmest ever observed in June, while the night from Monday to Tuesday ranked as the tenth hottest on record for any time of year. On June 23, the average maximum temperature was the third highest ever measured in June, exceeded only by the late-June heatwave of the previous year.
During the episode, 29 temperature records were set across 18 provinces, including three that had stood since 1920. Andújar, in Jaén, reached 45.1°C on Monday, and Montoro, in Córdoba, matched that reading the following day. These were the first temperatures of 45°C or more recorded in 2026. In total, 28 provinces saw temperatures of at least 40°C, while 129 of AEMET’s 828 stations reported such highs on Tuesday alone. Nearly half of all observatories recorded tropical, torrid or infernal nights: minimum temperatures stayed at or above 20°C, 25°C or 30°C, respectively.
Red alerts for extreme danger were issued in five provinces. Guipúzcoa and Vizcaya spent four consecutive days under the warning as forecasts called for sustained highs of 40°C or more. The heatwave set 13 records for daytime maximum temperatures and 16 for highest nighttime minimums. It affected A Coruña, Álava, Almería, Asturias, Baleares, Cantabria, Guipúzcoa, Jaén, León, Lugo, Madrid, Navarra, Ourense, Segovia, Teruel, Valladolid, Vizcaya and Zamora.
Several milestones were reached in northern Spain. On June 23, Tama in Liébana, Cantabria, recorded 43.7°C, the highest temperature ever measured in the region in any month. At Bilbao airport, where records date back to 1947, temperatures exceeded 40°C twice in 2026, matching the previous record for the most such days in a single year. Bilbao recorded seven days above 40°C between 1947 and 1999, compared with 13 since 2000.
The June episode formed part of a record-breaking national summer. AEMET data put Spain’s mean summer temperature at 24.5°C, the highest in the official series, which began in 1961, and 0.3°C above the previous record set in 2025. AEMET provisionally identified four heatwaves affecting mainland Spain and the Balearic Islands: June 20-27, July 2-24, July 28-August 20, and September 2-7. The season included 61 heatwave days, a record total in the cited national comparison.
AEMET’s longer-term figures show that heatwaves have grown more frequent and intense. Spain has experienced 78 heatwaves since 1975, totaling 458 days. There were 129 heatwave days before 2000 and 329 between 2001 and 2025. The average annual total rose from three days in the late 1970s and early 1980s to 22 in the last decade. Over each decade, the number of heatwave days has increased by about 3.3, while the area affected has expanded by an average of 3.2 provinces. Heatwave intensity has risen by 0.26°C per decade.
Extreme heat extended beyond land. The Balearic Sea averaged 24.2°C in June, 2.4°C above normal and the highest June temperature in the European Centre for Medium-Range Weather Forecasts series, which began in 1941. Near the end of the month, Mediterranean sea temperatures reached 26.63°C, 2.6°C above the usual level and comparable to readings more typical of the second half of August. At the Dragonera buoy near Mallorca, the sea reached 33.02°C, the highest reading recorded anywhere in that measurement network.
The effects were also evident in health and air quality. A study drawing on Spain’s MoMo mortality-monitoring system estimated 6,824 heat-related deaths across 90 Spanish cities during June-August. Its attribution analysis calculated that 5,227, or 77%, were linked to human-caused climate change. These are modeled estimates, not finalized civil-registration counts. Barcelona accounted for an estimated 1,587 excess heat deaths, with 88% attributed to human-caused warming. Across Europe, the study estimated more than 50,000 heat-related deaths over the summer, approximately 65% linked to anthropogenic warming.
Spain’s summer heatwaves also drove ozone pollution to its highest level since 2010. High temperatures can intensify the photochemical reactions that produce ground-level ozone, adding an air-quality hazard to the risks of sustained daytime heat and unusually warm nights.
Spain’s climate has become notably warmer in recent decades, with heatwaves arriving earlier and lasting longer. AEMET’s sequence of 2026 events unfolded amid exceptional warmth across western Europe: the region recorded its warmest summer in the cited Copernicus assessment, averaging 21.7°C, while a separate assessment put temperatures 2.9°C above the 1991-2020 reference period. Rising daytime and nighttime temperatures are putting growing pressure on public health and infrastructure, as well as daily life, particularly in regions less accustomed to such extremes.
