British dairy farmers delivered 240 million litres less milk than expected this summer after a run of record heat, with the lost volume valued at more than £83m, according to new analysis from the Energy and Climate Intelligence Unit.
The shortfall amounts to four fewer days of national milk supply between May and August. The heat damaged grazing conditions, stunted harvests and put livestock under heat strain across England and Wales, forcing many farmers to begin feeding herds winter rations months early, researchers said. Some, like Debbie Wilkins, a dairy and beef farmer in Gloucestershire, started bringing cattle indoors through the summer.
“The costs pile up when you have to bring the cows indoors and the loss of milk production compounds the issue,” Wilkins told the BBC of what she called a difficult season. The ECIU’s Tom Cantillon put the structural problem plainly: milk is an “unforgiving product in farming” because it cannot be stockpiled, so every hot day is production permanently lost rather than deferred.
The context is the UK’s hottest summer on record, with five intense heatwaves and drought declarations. Cantillon warned that future heatwaves would become progressively harder to recover from, and that more shade, trees and water on farmland is the adaptation route. The ECIU noted that dairy consolidation in recent years had allowed economies of scale and mechanisation to lift outputs while herd sizes fell, which cushioned this summer’s blow.
There is one genuinely surprising number in the release: despite the losses, UK milk production could still land near record levels in 2026. Farmers built up a production cushion earlier in the year that partially offset the summer shortfall, the ECIU said. Shelf prices are unlikely to reflect any of it at retail, since contracts smooth supply over months.
For the food industry the episode is a rehearsal. The same heat profile that cost dairy 240 million litres is forecast to become more common, and the sectors with perishable daily output, dairy, salad growers, soft fruit, have the fewest options. Unlike grain, you cannot put milk in a store and wait for a better year.