This year is on track to be the hottest year on record - and next year could be even warmer, the Met Office has said.
The latest data for 2015 suggests that by the end of the year, it will have been 0.72C above the country's long-term average.
But early indications point to 2016 being between 0.72C and 0.96C above that point, beating this year's record.
Forecasters say man-made global warming combined with the natural El Niño phenomenon in the Pacific is set to push the temperature gauge even higher.
With 2014 also one of the hottest on record, the Met Office's chief of long-range predictions, Prof Adam Scaife, said the predictions mean the UK will have seen temperatures hit unprecedented heights for three years in a row.
The Met Office does not expect the mercury to keep rising indefinitely, he added - but said it shows how global warming could combine with smaller natural fluctuations such as El Niño to affect the global climate.