This is an unofficial figure and has to be checked thoroughly. If you imagine that 25mm is a very wet day with rain all day for most places...
"Environment Secretary Hilary Benn, who is travelling to Cockermouth, said the situation was "very serious".
He told BBC Breakfast: "We have seen extraordinary amounts of rainfall. The rain gauge at Seathwaite registered 314mm [12.4in] in 24 hours which could make it the wettest day ever recorded, and we've seen the impact of that with the terrible flooding which has affected people."
http://news.bbc.co.uk/1/hi/uk/8366360.stm