British growers usually supply more than 90 per cent of the 150 million kilograms of fresh frozen peas that make up the market, which is worth £200m each year.
But according to British Growers Association chief executive James Hallett: "Many growers are forecasting at least a 40 per cent drop in their harvest, meaning a potential reduction in retail sales of up to £80m."
He added: "At this stage, shortfalls will not be made up in the remainder of the British season or with imports, since Europe has experienced similar conditions."
The harvest window for vining peas is short at around 10 weeks, five of which have already passed in central and southern Britain. But the season is just underway in Scotland.
Tayside grower East Coast Viners manager Fred Richardson said: "We are a fortnight late. We're in the middle of summer and it's 12 degsC here.
"It won't be a normal harvest by any means, but it all depends on the weather over the next two months. But the quality so far is looking good."