An average of 147 litres per square metre (147 mm) drenched mainland Spain last month, making it the wettest October since records began in 1961, national weather service AEMET and the ecological transition ministry said.

The deluge was 189 percent above the 1991-2020 reference period for the month and came as temperatures were 0.9 degrees Celsius warmer than average, they added in a statement.

The downpours peaked during a ferocious Mediterranean storm on October 29 which unleashed torrents of muddy water that desolated the eastern Valencia region in Spain's deadliest floods in decades.

At one measuring station in the Valencia region town of Turis, 771 mm of rain fell on that day alone.

Although Mediterranean storms are common for the time of year, scientists say climate change driven by human activity is increasing the intensity, length and frequency of extreme weather events.

The rainfall that triggered the floods was 12 percent heavier and twice as likely compared to the world before global warming, the World Weather Attribution group of scientists have said.