The total harvest is expected to be worth £20 million, double that of last year, and the fruit is "larger, sweeter and juicier" than farmers have seen in years, according to industry body British Cherries.
The fruit's "extraordinarily early" arrival in shops follows May being the sixth consecutive month of above-average temperatures, according to Met Office statistics, and the third warmest spring ever recorded - topped only by 2007 and 2011.
Orchards are also seeing an average drop in temperature from day to night of eight degrees, leading to firm, flavourful cherries with darker skin, British Cherries said.
The trade body, which represents more than 70% of growers, said total production was expected to double from last year to 4,000 tonnes.
Over the last decade the industry has invested in high-yielding trees that can be easily picked and covered for protection in the growing season.
During the 20th century Britain lost 90% of its cherry orchards, but between 2003 and 2008 they increased by 17%, according to Defra.
However the UK still imports around 95% of its cherries, mostly from Spain, Turkey and the US.
Those looking for home-grown varieties can buy 'Merchant' cherries now, distinguished by their dark red skin and large size, followed by others including 'Penny', 'Kordia' and 'Sweetheart', which ripens towards the end of the season.
A British Cherries spokeswoman said: "In total the British cherry harvest is expected to be £20 million, up from £10 million last year, and this year is set to last longer than ever, well into September.
"The many tonnes that are picked will find their way onto the supermarket shelves and summer social events, as consumers increasingly demand fresh home-grown produce."