The summer of 1976 is seared on to national memory as one of record heat. Harvests failed, farmers despaired, Britain imported an extra million tonnes of grain, food prices rose by 12%, taps ran dry, and each day, 250 people died from heat-related deaths.

The heatwave, which began 50 years ago on Tuesday, brought 15 consecutive days where the peak temperature was above 32C. Half a century later and 32C no longer feels shocking.

On Monday the UK Health Security Agency (UKHSA) issued its second ever red heat health alert for six regions of England, while the Met Office issued a rare red weather warning for Wednesday and Thursday. With temperatures predicted to pass 40C, people are being advised to close doors and windows and shut curtains to stay cool at home.

“When I was a child, sunny summer days felt exciting. I do not want drawn curtains and closed windows to become the defining image of [my child’s] summer,” said Stephanie Robson, of Parents for Future, in a moving address with her six-month-old child at a summer of 1976 anniversary event organised by the Met Office.

The event, held in an air-conditioned basement in King’s Cross, brought together MPs, policymakers and members of the public spanning multiple generations, several of whose phones lit up as the UKHSA issued its red warning.

While the 1976 heatwave was an extraordinary weather event, it took place in a much cooler world. In the past 50 years, average global temperatures have risen by about 1C. But for southern England, this number is between 3C and 4C.

“This increase is roughly what we’re seeing in today’s forecast,” said Ed Hawkins, professor of climate science at the University of Reading.

“Greenhouse gas emissions, primarily from burning fossil fuels, means British summers have already become hotter. Our new research shows that a comparable event to 1976 would be 3 degrees hotter today,” he said. “Our summers are becoming increasingly unrecognisable.”

While ingrained in national memory, 1976 is the sixth warmest summer on record, with the summer of 2025 topping the rankings – for now.

The Met Office has issued a new projection of what a heatwave like that of the 1976 summer could look like in the 2050s. Under this modelling, the UK could see a 14-day heatwave event with temperatures of over 40C for nine consecutive days. Temperatures could peak at 45C in England, 38C in Scotland, 41C in Wales and 30C in Northern Ireland.

“This is only plausible because of high greenhouse gas emissions, the majority of which come from burning fossil fuels,” the Met Office said in a statement.

Laura Tobin, English broadcast meteorologist and scientist, remembers reporting on the first red heat health alert in the summer of 2022.

“I remember I stood there and said that temperatures will reach 40 degrees and the reality hit me. I just had to take a moment and go to my room and realise what I said and what it meant, that people will die,” said Tobin.

“And they did. It played out that nearly 3,000 people died in the UK and 61,000 people died across Europe. The reality in [today’s heatwave] is that people will die. It has stopped becoming a hot weather story and it has become an extreme weather story.”

Alongside record heat, 1976 also brought historic drought, when many homes across the country did not have running water and depended upon standpipes.

New modelling by Hayley Fowler, professor of climate change impacts at Newcastle University, shows that if the same heatwave were to happen today, it would be 20% dryer and the water deficit would be 10% greater.

Without investment to reduce water leakage, build more reservoirs and to create better water storage, England alone could face a public water supply shortfall of about 5bn litres per day by 2055.

“What was extraordinary for my mother’s generation, is not extraordinary for my children,” said Emma Pinchbeck, chief executive of the Climate Change Committee. “Even if we cut emissions, we need to prepare for a fundamentally different climate to the one of 1976.”

The Climate Change Committee puts “a cost on almost anything”, said Pinchbeck, “but as a mother I have found no relative cost to the grief of what my child will lose”.