The average temperature across the country hit 24.08C, breaking the previous record for the month of 23.73C set on May 21, 2022, according to provisional data from the agency.

"This was the hottest day for a month of May across mainland Spain since the beginning of the data series in 1950," AEMET wrote on social media.

The average temperature on Saturday reached 23.91C, making it the second-hottest May day on record.

A mass of hot air moving north from Africa pushed temperatures in some areas of Spain more than 10C above normal for the time of the year.

Temperatures exceeded 40C in parts of southern region of Andalusia.

While unusual, this is not the first time Spain has experienced exceptionally high May temperatures. Similar events occurred in 2015 and 2022, AEMET said.

"This reflects a scenario where summer-like conditions are arriving earlier and more frequently, even before spring has ended," said AEMET spokesperson Ruben del Campo.

Scientists say climate change driven by human activity is increasing the length, frequency and intensity of extreme weather events such as heatwaves.

The last three years have been the hottest on record in Spain, which is emerging from a years-long drought.