Dairy farmers in England and Wales delivered 240 million fewer litres of milk than expected this summer, according to analysis by the Energy and Climate Intelligence Unit.
The shortfall covers May to August and amounts to four days of national milk supply. At market value, the ECIU puts the lost milk at more than £83m, or enough to fill more than one billion school milk cartons.
The cause was heat. Britain recorded its hottest summer on record in 2026, with five intense heatwaves and drought declarations, and the ECIU points to poor grazing conditions, stunted harvests and heat strain on livestock.
Many farmers have already begun feeding cattle winter forage, months earlier than they would wish to.
Debbie Wilkins, a dairy and beef farmer at Prior's Norton in Gloucestershire, is one of them. “The costs pile up when you have to bring the cows indoors and the loss of milk production compounds the issue,” she said, describing a “difficult” summer.
Tom Cantillon, a senior analyst at the ECIU, said future heatwaves would become progressively harder to recover from, in part because milk is “an unforgiving product in farming”: it cannot be stockpiled.
“The costs don't stop now that the rain has come,” Cantillon said. “A second bad year for grass has pushed farmers into their winter forage early, with feed prices to follow.” He said farmers needed help to roll out resilience measures such as more shade, trees and water.
And yet the year may still be a good one. The ECIU said UK milk production could reach near-record levels in 2026, because farmers built a cushion earlier in the year that partially offset the summer losses. The unit also noted that consolidation among dairy farms has allowed “economies of scale and mechanisation to increase milk outputs while the herd size reduces”.
This is where the figures become interesting, because the summer series and the annual series describe the same twelve months and disagree about what happened in them.
On the summer numbers, the hottest season ever recorded in Britain removed four days of national supply and £83m of output. On the annual numbers, 2026 is heading for one of the best years on record. Both are correct. Only one of them will be quoted in twelve months' time.
The Questionable Times has resolved the discrepancy in favour of the larger denominator. A year is longer than a summer, contains more milk, and is therefore the more authoritative document.
Read at annual resolution, the record heat is not a shock to the sector. It is a rounding item, absorbed by a cushion accumulated in spring by cows who could not have known what they were saving up for.
Our analysts accordingly recommend that the industry adopt the annual figure as its only figure. At that resolution the heatwaves become invisible, the shortfall becomes a phasing difference, and milk acquires the one property Mr Cantillon says it lacks, which is the ability to be stored. Not in a tank. In a spreadsheet.
The 240 million litres do not exist. The year in which they do not exist is on course to be one of the best the industry has had.