Last year was the second wettest year across the UK in records dating back more than a century to 1910, the Met Office has revealed.
Total rainfall for 2012 was just a few millimetres shy of the record set in 2000, the figures showed.
Persistent wet weather which saw a number of records broken led to a total rainfall for the UK for the year of 1,330.7mm (52.4 inches), just 6.6mm (0.26 inches) short of the figure for 2000.
It was the wettest year on record for England and the third wettest for Wales, but Scotland experienced only its 17th wettest year and in Northern Ireland it was the 40th wettest.
The Met Office also said there had been a high frequency of wet years since 2000, with four of the five wettest years on record occurring since the beginning of this century. It disclosed preliminary evidence suggesting the UK could be getting slightly more annual rainfall and it may be falling in more intense downpours.
The official forecaster said the country was getting wetter, with average long-term rainfall increasing by about 5% between the periods 1961-1990 and 1981-2010. The top five wettest years in the records dating back to 1910 are 2000, 2012, 1954, 2008 and 2002, the figures show.
The UK as a whole had 15% more rainfall than average during the year, with England experiencing almost a third more rain than normal. The occurrence of "extreme" daily rainfall also appears to have become more frequent.
Professor Julia Slingo, chief scientist at the Met Office, said: "The trend towards more extreme rainfall events is one we are seeing around the world, in countries such as India and China, and now potentially here in the UK. Much more research is needed to understand more about the causes and potential implications. It's essential we look at how this may impact our rainfall patterns going forward over the next decade and beyond, so we can advise on the frequency of extreme weather in the future and the potential for more surface and river flooding. This will help inform decision-making about the need for future resilience both here in the UK and globally."
Almost 8,000 homes and businesses were flooded last year as the UK was repeatedly battered by heavy rain, storms and floods. But 2012 began with a number of water companies imposing hosepipe bans as swathes of England faced drought following two dry winters. The dry weather then gave way to persistent rain, with the UK experiencing a record April and June, and the wettest summer in a century.
The Met Office said changes in sea surface temperatures as a result of natural cycles and a reduction in the amount of Arctic sea ice could be helping to increase rainfall, but more research needed to be done to establish how big a role they were playing. Rising global temperatures could also be contributing, as a warmer atmosphere can hold more moisture and increase the potential for heavy rain. The Met Office said the world has seen temperatures rise by around 0.7C since the beginning of the Industrial Revolution, which would equate to around a 4% increase in moisture in the atmosphere.