29 March 2022, UK: The Met Office has raised the temperature that it now defines as a heatwave, to reflect the changing climate and the increased incidence of hot weather across the country. The incidence of heatwaves is predicted to become far more frequent.
Heatwave threshold rises have been greatest across eastern and central England – indicating the potential impact on the UK’s primary potato and sugar beet cropping areas.
Although heatwaves are extreme weather events, research shows that climate change is making these events more likely.
The heatwave thresholds for Lincolnshire and the East Riding of Yorkshire have both risen by a full 1⁰C, to 27⁰C and 26⁰C respectively. In Cambridgeshire a heatwave is now declared with three consecutive days when the temperature exceeds 28⁰C.
Analysis of weather patterns over recent periods show how heatwaves under the new criteria are becoming more common (above) Source: Met Office
Dr Mark McCarthy, head of the Met Office National Climate Information Centre, highlighted that some regions have experienced more rapid change than others. “Climate statistics over time reveal an undeniable warming trend.
A scientific study by the Met Office revealed the 2018 heatwave was 30 times more likely to occur than in 1750, for example, because of the higher concentration of carbon dioxide in the atmosphere, acting as a greenhouse gas.
“As greenhouse gas concentrations increase, heatwaves of similar intensity are projected to become even more frequent, perhaps occurring as regularly as every other year,” warned Dr McCarthy.