Saturday 3 October was the wettest day for UK-wide rainfall since records began in 1891, Met Office researchers have said.
The downpour followed in the wake of Storm Alex and saw an average of 31.7mm (1.24ins) of rain across the entire UK.
The deluge was enough to exceed the capacity of Loch Ness - the largest lake in the UK by volume - the researchers added.
The previous record wettest day was 29 August 1986.
It has been a year of stark contrasts across the UK when it comes to rainfall.
Two named storms, Ciara and Dennis, helped push February to the top of the records as the wettest ever in the UK.