The Met Office said 2022 saw the highest annual average temperature recorded across the UK, exceeding the previous record set in 2014 when the average was 9.88C.
Since records began in 1884, all 10 years recording the highest annual temperature have occurred since 2002, it added.
The forecaster said all four seasons in 2022 were in the top 10 warmest for the UK.
Winter was the eighth warmest, spring the fifth, summer the fourth and autumn the third.
According to the Met Office, 2022 will also be the warmest year on record in the 364-year Central England temperature series from 1659, the world’s longest instrumental record of temperature. The exact figure will be confirmed in the new year.
Dr Mark McCarthy, head of the Met Office's National Climate Information Centre, said: “2022 is going to be the warmest year on record for the UK. While many will remember the summer's extreme heat, what has been noteworthy this year has been the relatively consistent heat through the year, with every month except December being warmer than average.
“The warm year is in line with the genuine impacts we expect as a result of human-induced climate change. Although it doesn't mean every year will be the warmest on record, climate change continues to increase the chances of increasingly warm years over the coming decades.”
The year started with a mild theme with New Year’s Day the warmest on record according to maximum temperature.
A temperature of 16.3C was recorded at St James’s Park, London, and that mild theme was replicated through much of 2022 with more warmer-than-average days and fewer cooler-than-average days.
Temperatures remained above average for every month of the year in 2022, except December which has been cooler than average so far.
While many will remember the unprecedented heat in July, it is the persistence of warmer-than-average conditions that resulted in 2022 breaking the annual temperature record.
Rebecca Newsom, head of politics at Greenpeace UK, said: “These aren't the kind of records you want to be breaking. I’m sure most of us would rather see record-breaking investment in the renewable technologies that’ll get us out of this mess.
“People around the world are already suffering the devastating consequences of climate breakdown, despite having done little to cause it, like the severe flooding in Pakistan recently.
“You don’t have to look far to see the accelerating impacts of the climate crisis: increased flooding, unseasonable temperatures and erratic weather systems are becoming the norm.
“The government can’t just talk big on the world stage.”
The fourth warmest summer in the series for the UK was underlined with temperatures in excess of 40C recorded in the UK for the first time. Coningsby, Lincolnshire, recorded the highest temperature, with 40.3C exceeding the previous UK record by 1.6C.
Summer was the tenth driest on record for the UK, with the south and east of the country especially dry. Some locations in southern and eastern England recorded virtually no rain in July, and by the end of August, the year had been at its driest at that point since 1976.
Dr Mark McCarthy added: “Despite the recent rain, the year has still been dry for much of the country, especially so in the south and east.”
Norfolk, Suffolk and Essex are all on course to record a year in their respective top 10 driest on record. The exact positioning will be dictated by how wet the last few days of December are.
The south of England has so far had only just over three-quarters of the rainfall it would normally expect in a year.
A total of four storms were significant enough to be given names in 2022 and three of them came within the space of a week.
Storms Dudley, Eunice and Franklin hit the UK in February 2022, with Storm Eunice resulting in red warnings for wind and saw a new highest maximum gust speed record for England set of 122mph at the Needles on the Isle of Wight.
Dr Mark McCarthy said: “There’s no evidence of a trend in storminess because of climate change, but this spell of impactful weather in February is certainly noteworthy. It was the first time three named storms had impacted the UK in a week, with Eunice being particularly impactful for much of southern England and Wales.”