The Met Office said there could be maximum temperatures of 21C (69.8F) on Tuesday in areas across the south and south-east of England which would beat Monday's winter record of 20.6C (68.5F) at Trawsgoed in Ceredigion, west Wales.
London will hit around 20C (68F) and Lerwick in the Shetland Islands will have temperatures up to 11C (51.8F), above the February average.
The unseasonable weather drew surfers to the seas in Boscombe beach, Dorset, to brave the relatively cool water temperatures.
Met Office meteorologist Grahame Madge said: "We're expecting warmer temperatures than yesterday. The record of 20.6C (69.08F) in Wales is likely to be broken in the south or south-east.
"There is a large area of high pressure that moves in a clockwise direction bringing warm winds from the Canary islands, meaning more sunlight.
"The dry ground needs less energy to heat up and so it will become hotter, easier - this, combined with the southern air flow, will make it very warm."
Temperatures in the south of England will be similar to tourist hotspots around Europe, with places such as Benidorm, Mallorca and Ibiza all registering cooler weather.
The warm weather is in stark contrast to this time last year, when the UK was swept by the "Beast from the East" which brought heavy snow showers and lows of minus 5C (23F), leading to travel delays and power cuts in what were the lowest temperatures in the week leading up to March 1 since 1986.
Last year's cold weather was down to a similar weather pattern, but the high pressure instead came from Arctic Russia, moving over Scandinavia.
The conditions seen this week come from the tropic Atlantic and parts of North Africa.
However, by Thursday the weather from the Atlantic will bring colder showers, with temperatures dropping significantly, the Met Office said.
Heavy showers are possible as temperatures will struggle to get above 11C (51.8F) or 12C (53.6F).