A 16-day heatwave Spain suffered this month was "the most intense on record", the national meteorological agency said on Sunday.
With forest fires still burning across northern and western Spain, the AEMET meteorological agency said provisional readings for the August 3-18 heatwave exceeded the last record, set in July 2022, and showed an average temperature 4.6C higher than previous events.
AEMET said a 10-day period from August 8 to August 17, was the hottest 10 consecutive days recorded in Spain since "at least 1950".
The August heatwave exacerbated tinderbox conditions that have fuelled wildfires which have killed four people and forced thousands out of their homes.
Four people have also died in fires in Portugal, where emergency services are still struggling to control the blazes.
More than 1,100 deaths in Spain have been linked to the August heatwave, according to an estimate released Tuesday by the Carlos III Health Institute.
The institute had already said that 1,060 deaths in July could be attributed to excess heat, a 50 percent rise on the figure for July 2024.
Since it began keeping records in 1975, AEMET has registered 77 heatwaves in Spain, with six going 4C or more above the average. Five of those have been since 2019.
Scientists say climate change is driving longer, more intense and more frequent heatwaves worldwide.
The agency said that it is "a scientific fact that current summers are hotter than in previous decades".
"Each summer is not always going to be hotter than the previous one, but there is a clear trend towards much more extreme summers. What is key is adapting to, and mitigating, climate change," it added.
Fires burning in northern regions have destroyed more than 350,000 hectares (865,000 acres) in the past weeks and a record of more than 400,000 hectares since the start of the year.
Authorities say they are only now starting to control the fires.
Firefighters and water-bombing planes from nine European countries have been helping Spanish emergency services.
Hundreds of people are still kept away from their homes though many have started returning in the past 24 hours.
Portugal announced its fourth fatality from the current wildfires on Saturday. The 45-year-old fireman had been critically injured battling the flames last week.
More than 60,000 hectares of land have burned in Portugal in the current heatwave and more than 278,000 hectares since the start of the year.
