Flooded land has ruined British rapeseed crops and made it harder to plant for the next harvest.
Yields are likely to be down 38 per cent this year as a result.
Britain relies on rapeseed oil since sunflower oil prices have soared amid the Ukraine war.
Chippies, restaurants and catering companies will be hit, trade magazine The Grocer warns
Overall, climate change has added up to £361 to the typical annual UK food bill, say analysts.
Tom Lancaster, at the Energy and Climate Intelligence Unit, said “We’re seeing a double whammy on cooking oil.
“Be it Spanish olive oil or British vegetable oil, climate extremes are hurting crops and consumers are paying for it at the supermarket checkout.
“The failure of the British rapeseed oil harvest could see a hike in vegetable oil prices.
“These kinds of extremes, both in the UK and abroad, will only worsen until we reach net zero emissions, making it essential to protect our food security.
“But farmers both here in the UK and abroad are going to need our help.”
“British farmers will need short-term support this year to cope with flooding and crop failures, but also longer-term support such as the government’s environmental land management scheme to help them improve soil health and protect land from flooding with more hedgerows and trees.”