Provisional figures for the whole year reveal that it was the hottest for the UK in records dating back to 1910.
Last year was also the warmest in the Central England Temperature series, the longest running temperature record in the world which stretches back to 1659, recording temperatures in an area of central England.
The average temperature for the year was 9.9C (49.8F), some 1.1C (2F) above the long term average, and making it warmer than the previous record year of 2006.
It was also the fourth wettest year in records dating back to 1910, the Met Office said.
The figures for 2014 mean that eight of the UK’s top 10 warmest years have occurred since 2002, the weather and climate experts said.
Across the UK, it was the warmest year on record for all countries and regions apart from Northern Ireland, which had its third warmest year behind 2007 and 2006, the figures show.
There were no record-breaking hot months in 2014, but temperatures were consistently warm with only August experiencing below average temperatures.
The number of air frosts in the UK was the lowest in records dating back to 1961, the provisional figures show.
Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment London School of Economics (LSE) said the record temperatures in 2014 were “part of a pattern”, with most of the hottest and wettest years occurring since 2000.
“This is clear evidence of the impact of man-made climate change on the UK,” he said.
“However, the latest assessment by the independent Committee on Climate Change shows that the UK public is largely unaware of how climate change is affecting their exposure and vulnerability to extreme weather events.
“The lack of awareness of the UK public of how climate change is already affecting them represents a colossal failure by the Government and its agencies, including the Environment Agency and the Met Office, to communicate with the public about this issue.”
The Met Office figures show that the provisional rainfall total of 1297.1mm (51.1 inches) is the fourth highest total on record, meaning five of the six wettest years in the UK have happened since 2000.
A large contribution to the high rainfall total came from the very wet weather in January and February, as a series of storms battered the UK, while May, October and November were also wetter than average.
But September was the driest on record since 1910 for the UK.
The most extreme weather in 2014 was the winter storms, which caused flooding both inland and at the coasts, while the summer had some fine weather, particularly in June and July, with no heat waves but some torrential downpours. the Met Office said.