The exceptional rainfall in Cumbria over the past few days saw the fall of numerous records and has led many to ask whether it is linked to climate change. The records are based on digitised data going back to the 19th Century.

A gauge at Honister Pass recorded 341.4mm of rainfall in the 24-hours up to 1800 GMT on 5 December 2015, making for a new UK record for any 24-hour period. This beat the previous record of 316.4mm set in November 2009 at Seathwaite, also in Cumbria. A new 48-hour record (from 0900 to 0900 hrs) was also set, when 405mm was recorded at Thirlmere in Cumbria in just 38 hrs.

The weekend’s record rainfall was associated with a persistent, south-westerly flow bringing a ‘river of moisture’ from as far away as the Caribbean and the Gulf of Mexico. Ocean temperatures in the West Atlantic are currently well above normal and may well have contributed to the very high levels of moisture in the air masses which unleashed rainfall on the Cumbrian fells.

Professor Dame Julia Slingo, Met Office Chief Scientist, says “It’s too early to say definitively whether climate change has made a contribution to the exceptional rainfall. We anticipated a wet, stormy start to winter in our three-month outlooks, associated with the strong El Niño and other factors.

“However, just as with the stormy winter of two years ago, all the evidence from fundamental physics, and our understanding of our weather systems, suggests there may be a link between climate change and record-breaking winter rainfall. Last month, we published a paper showing that for the same weather pattern, an extended period of extreme UK winter rainfall is now seven times more likely than in a world without human emissions of greenhouse gases.”