Britain's topsy turvy weather means that spring has come four months early with this December being the warmest on record, according to latest figures from the Met Office.
As storms and floods continue to batter communities across northern parts of the UK, experts also revealed that it had been the second wettest December in more than 100 years.
Across the the country an average 211mm of rain fell during the month. Only December 1929 was wetter, with 213mm of rain.
Scotland and Wales both had their wettest December since 1910, the earliest year on record - 333.1mm and 321mm respectively.
December temperatures for the whole of the UK reached a spring-like 8C, which is 4.1C above the long-term average. The previous record was 6.9C, set in 1934.
The Met Office said: "This means the temperatures this December 2015 were closer to those normally experienced during April or May."
This year is on course for being one of the 10 wettest on record in the UK. The wettest year was 2000, when 1,337mm of rain fell across the country. Provisional figures for the year up to December 29 show 1,270mm of rain.
Storm Desmond was largely responsible for making December a record-breaking month, say the experts, with unprecedented amounts of rain falling on the Lake District.
The Christmas period was described as "unsettled, wet and mild". Hard on the heels of Storm Desmond, Storm Eva brought more gales and heavy rain to many northern areas on Christmas Eve, then Storm Frank moved in to cause more mayhem, with Scotland and Northern Ireland bearing the brunt.
December has also been the fourth wettest on record in Northern Ireland, said the Met Office. But rainfall levels have been much closer to average in central and southern England.
Experts lined up to make the connection between the extreme weather and global warming.
Climate scientist Professor Piers Forster, from the University of Leeds, said: "There is no doubt in my mind that climate change is partly responsible for the flooding across the north of England. These floods are in part due to greenhouse gas emissions."
He said the unusually high temperatures resulted from the combined effect of a strong El Nino ocean-warming system in the Pacific and a man-made global warming trend.
Professor Myles Allan, from the University of Oxford, said: "The weather has changed, and we have changed it: get used to it.
"Those with more open minds are asking, 'is this the new normal?'. Unfortunately, the answer is 'no' - 'normal weather', unchanged over generations apart from random fluctuations, is a thing of the past. When families reconvene for Christmas in the 2040s, the envelope of 'normal weather' will have shifted by as much again as it has already shifted since the 1970s."
Meteorologist Paul Williams, from the University of Reading, said "simple physics" showed that warmer air holds more water vapour. He added: "The global warming that we have experienced so far has increased the atmosphere's moisture storage capacity by about 7%. This is undisputed science and it clearly increases the potential for extreme rainfall and flooding."
Professor Chris Rapley, from University College London, said while it was difficult to detect long-term trends in rainfall, a "robust" pattern of increasing precipitation had been seen in northern hemisphere mid-latitudes.
"Attribution of precipitation trends suggest evidence of human influence at latitudes similar to that of the UK," he said.