Why summer 2026 was the UK’s hottest on record: Key reasons explained

On Tuesday, the UK has tentatively recorded its hottest summer on record in 2026, bringing prolonged heatwaves, high temperatures, and a water crisis across the country.

According to reports, an average mean temperature of 16.5 °C puts this summer the warmest on record, along with the warmest season for the UK in a series which dates back to 1884. This was one of the sunniest summers on record with the season remaining dry.

In this connection, Dr Amy Doherty at the Met office stated: “The conditions we’ve seen this summer have broken UK climate records once again. These records are now breaking with increasing frequency, reflecting the influence of human-induced climate change on the temperatures we’re experiencing in the UK.

“Particularly notable is how much we’ve exceeded the previous summer mean temperature record, set just last year. The figures also knock the infamous summer of 1976 down to seventh for average summer mean temperature, with the top five warmest summers all occurring since 2003.”

Forecasts indicated that the UK started the meteorological summer with the second warmest June on record after the second warmest July. A real-time climate attribution study conducted by Met Office scientists has shown that record-breaking summer was made around 130 times more likely because of anthropogenic climate change.

Head of Climate Attribution at the Met Office, Dr Mark McCarthy said: “Our analysis shows a summer like the one we’ve just experienced is now around 130 times more likely because of climate change. In a climate unaffected by human emissions of greenhouse gases, a summer like this would be exceptionally unlikely, i.e. 1 in over 1,000 years. In our current climate, which is changing because of the effect of burning of fossil fuels, we should now expect this to be roughly a 1 in 9-year event.”

“The attribution study we conducted at the end of summer 2025, which at the time was record breaking, found that we could experience even hotter summers in our current climate. Just a year later we’re already seeing this play out, with the 2026 summer average temperature 0.40°C higher than 2025, a significant margin for a seasonal temperature.”

Furthermore, reports from the UK indicated its sixth sunniest summer on record with 621.9 hours of sunshine. England and Wales also experienced their individual second-sunniest summers ever recorded.