In a new study, the Met Office also concluded that human-induced climate change made the record-breaking temperatures around 160 times more likely.
Without climate change, it was estimated that such temperatures would only be experienced in around one in 500 years, but it is now likely they will recur every three to four years under current climate conditions.
The full annual UK mean temperature data for 2022 resulted in a provisional figure of 10.03°C, the highest yet in records dating back to 1884. This made 2022 0.89°C above the 1991-2020 average and 0.15°C higher than the previous record of 9.88°C set in 2014.
Dr Nikos Christidis, Met Office climate attribution scientist, said: "We also used climate models to project how often this sort of temperature could be recorded in the future. It was possible to calculate that by the end of the century, under a medium emissions scenario (SSP2-4.5), a UK average temperature of 10°C could occur almost every year."
In addition, 2022 was also the warmest year on record in the 364-year Central England Temperature (CET) series from 1659, the world's longest instrumental record of temperature.
After a notably warm start to the year in 2022, with New Year's Day the warmest on record, the mild theme was replicated through much of the year with many more "warmer than average" days than "cooler than average" days.
The annual mean temperature reached record-breaking levels during the exceptional heatwave in July and despite a notable cold spell in December remained at record levels for the year overall.
Dr Mark McCarthy, head of the Met Office National Climate Information Centre, said: "Although an arbitrary number, the UK surpassing an annual average temperature of 10°C is a notable moment in our climatological history.
"This moment comes as no surprise: since 1884, all the ten years recording the highest annual temperature have occurred from 2003. It is clear from the observational record that human-induced global warming is already impacting the UK's climate."
The evidence of the UK's changing climate can also be seen in the distribution of hot and cold annual records.
Over the same timespan, since 1884, the Met Office has not recorded a top ten coldest year in 60 years (1963 ranks as the fourth coldest year in the series), with most of the top 10 coldest years clustered before 1920.
"Even with the influence of climate change, we don't expect every year to be the hottest on record from now on," Dr McCarthy explained. "Natural variability of the UK climate means there will always be some variation year to year. However, looking at longer-term trends, it is easy to pick out the influence climate change is having over time."
