Gravesend in Kent had the highest temperature in the country today, recording 20.5C (68.9F) at 2.30pm, according to the Met Office.
The last time the 20C mark was breached in Britain was on October 8 last year.
Many of us will have a perfect spring day with unbroken, clear blue skies and sunshine.
More cloud will remain across the north-west with dull, damp conditions for Scotland and Northern Ireland - the rain pepping up later.
Away from the cloud in the north-west, a remarkably mild climate for the time of year and people will be feeling warm in the south, with temperatures peaking at 17-18C inland - and possibly 19C. Coasts will be prone to a cool sea breeze.
Britain is set to bask in the highest temperatures of the year so far on Sunday - warmer than some holiday spots in the Mediterranean, according to forecasters.
The Met Office says temperatures will reach 18C (64.4F) in parts of England - and "exceptionally mild" for the time of year and above places such as Greece and Turkey.
Saturday's highest temperature was recorded at 16.6C (61.9F) at around 2pm in St James's Park in central London.
Tomorrow should be another fine, bright day again with unbroken blue skies and sunshine.
The glitch will be cloudy, breezy and damp conditions for western Scotland and Northern Ireland, the rain pepping up later. Eastern Scotland will get away with a better day.
Away from the cloud and rain, it will be remarkably mild for the time of year.
Across the south-east it will be warm for early March with highs of 18C or possibly 19C - rivalling temperatures across southern Europe and the Med.
We'll be warmer than parts of Italy and Greece.
The recent spell of warm weather is set to continue tomorrow - with top temperatures in the capital set to beat holiday spots in Spain and the South of France.
Highs are expected to reach 18C in London tomorrow - whereas Majorca will see around 17C and luxury hotspot St Tropez just 15C.
St James' Park saw the hottest temperature of the year yesterday at 16.9C.
Overnight tonight warm winds from the south will keep temperatures mild, with clear skies expected all day tomorrow across the capital.
English strawberries have gone on sale in supermarkets after the very wet but mild winter helped them ripen early.
Waitrose confirmed it has native strawberries in selected stores in time for what is predicted to be the hottest day of the year tomorrow, with temperatures reaching 18C in some parts of Britain, a week earlier than last year.
There will be a slow start in the morning with cloudy skies.
Scotland and Northern Ireland will be very windy and wet and patchy rain will seep into the north-west of England and Wales before easing.
But in the afternoon it will cheer up with brighter skies developing. There will be plenty of sunshine for most, with many places staying mild.
Highs will reach 16c or 17c in the south. Elsewhere temperatures will remain above average for the time of year.
On Sunday, temperatures will possibly peak nearer 18c across the south-east making it warmer than some spots of the Mediterranean.