The national meteorological agency, AEMET, reported that the August heatwave reached a temperature anomaly of 4.6°C, surpassing previous records. Based on observed data and forecasts through 31 August, summer 2025 is set to be one of the two hottest summers in Spain's history, clearly ahead of the 2003 record-breaking season.

Warm spells dominated most of the year, with only March being notably cold and May close to average. From January to August, 2025 ranks as the second warmest year on record, just behind 2024, creating a trend of consistently high temperatures over the past four years.

Record-breaking August heatwave

The August heatwave lasted 16 days, with the period from 8 to 17 August being the hottest ten-day stretch ever recorded in Spain since at least 1950. Five of the country's 20 warmest periods on record occurred during this heatwave, and 15 of the 20 hottest periods overall have happened since 2022. AEMET noted that "the persistence of extreme heat intensifies its adversity," warning that the event raised fire danger and threatened public health.

Although temperatures briefly cooled after 18 August, forecasts indicate that high heat will return before the month ends, continuing the pattern of extreme summer conditions.

Climate change driving extreme summers

Spain's average temperature has risen 1.69°C since 1961, increasing the frequency and intensity of heatwaves. Scientists report that summer heatwaves are becoming longer, more widespread, and more severe, with both daytime and nighttime temperatures reaching higher extremes than in previous decades.

Climate projections suggest that by mid-century, Mediterranean summers could be around 2°C warmer than those from 1981–2020. Alarmingly, the summers of 2022 and 2025 already resemble these mid-century conditions. The repeated intensity of recent heatwaves underlines the influence of climate change and underscores the urgent need for both adaptation and mitigation measures to protect people, ecosystems, and infrastructure.