December deluge led to 'record-breaking rainfall and river flows'
Further evidence of the extraordinary weather conditions last month has been revealed, with some areas seeing record-breaking river flows, rainfall and groundwater levels.
Three rivers had the largest flow ever recorded for rivers in England after Storm Desmond, one of a series of storms that brought heavy rainfall and flooding last month, according to the Centre for Ecology and Hydrology (CEH).
The Eden and Lune in north-west England and the Tyne in the North East all recorded flows of around 1,700 cubic metres per second, many times the average rate of 53 cubic metres per second for the Eden, 45 for the Tyne and 36 for Lune.
The flow of 1,700 cubic metres per second is the equivalent of 41 Olympic swimming pools of water going past the measuring gauge every minute - a rate that would fill the Royal Albert Hall in less than a minute, the experts said.
There were also exceptional flows in the Boxing Day flooding, with many large rivers coming out of the Pennines experiencing their highest flows in records dating back more than 50 years, including the Nidd, Wharfe, Aire and Irwell.
Many rivers also saw exceptionally average flows for December as a whole, as th e UK was hit by the wettest month in records dating back to 1910 following a wet November that had already seen rivers on the rise.
Figures from the Met Office have shown new 24-hour and 48-hour rainfall records, with 341.4mm (13.4 inches) of rain at Honister Pass, Cumbria over a 24-hour period during Storm Desmond - a level of rainfall considered to be a one-in-1,300 year event.
In 48 hours during the same storm, Thirlmere in Cumbria received 405 mm (15.9 inches).
Over the month, Cri b Goch in Snowdonia recorded 1,396mm (55 inches) of rain over the month - among the largest monthly totals ever recorded in the UK.
Most northern and western parts of the UK saw more than double the average rainfall for the month, while upland areas in the Lake District, north Pennines and the Cairngorms had three times their normal levels of rain, the summary showed.
The heavy rainfall and high river flows led to devastating flooding, in which thousands of homes and businesses were inundated, bridges collapsed, landslides were caused and transport and infrastructure were hit.
Groundwater levels were generally normal or above in December, but exceptional rainfall in the northern half of the UK saw record monthly levels in spots such as Killyglen, Northern Ireland, and Newbridge, Scotland.
The assessment warned that with exceptional wetness and flooding continuing into January in parts of northern Britain, the risk of further flooding early in 2016 remained high.
Jamie Hannaford, head of the National Hydrological Monitoring Programme at the Centre for Ecology and Hydrology, said the widespread nature of the sustained, very high river flows in December was "remarkable", adding that "many large catchments in northern Britain recorded their highest ever peak flows and/or monthly mean flows".
He added: "The three largest flows ever registered in river flow records for England occurred on the Eden, Lune and Tyne."