The temperature matched the September record of 45.7°C set in Montoro in 2016, another town in the southern region of Andalusia, AEMET said on social media.

It was also the highest temperature registered in Spain this year in a week where summer-like heat topping 40C has baked swathes of the south and west of the country.

The unseasonal September heat comes after a string of exceptional summer heatwaves seared Europe, which scientists say human-driven climate change has intensified and lengthened.

The extreme temperatures have been linked to thousands of excess deaths across the continent, disrupted the economy through drought and low river levels and broken heat records.

AEMET briefly issued the highest red alert for heat in small areas of Andalusia on Thursday -- the first time such warnings had been sent in September since they started in 2007.

It also announced on Thursday that mainland Spain had sweltered through its hottest January-August period on record, "with a clear difference" on the four next highest readings for the period -- which were the four previous years.

"It is an unmistakable sign that, in Spain, warming is accelerating," said AEMET, which had already announced that July was the country's joint-hottest month on record.