A current heatwave is feeling more intense than previous ones, according to scientists, due to higher humidity levels. While the day-to-day climate in Britain is not notably humid compared to other regions like the subtropics or Persian Gulf, this heatwave is nearly twice as humid as recent hot periods, posing health risks such as heatstroke and cardiovascular issues.
Some parts of the country under a red heat health warning could experience temperatures feeling warmer than during the 2022 heatwave, despite lower actual temperatures, due to the ‘wet bulb’ effect caused by high humidity hindering natural body cooling through sweat evaporation.
Regius Professor Hannah Cloke from the University of Reading highlighted that the combination of heat and humidity is crucial, with this week’s forecast showing higher humidity levels at lower temperatures than in 2022, making the body work harder to cope with the conditions.
The Met Office warns of health risks from high humidity, including heat stress, dehydration, and in severe cases, heatstroke and cardiovascular complications, especially affecting vulnerable groups such as the elderly and those with existing health conditions.
Forecasters predict that temperatures could feel as high as 50C due to the humidity, even if the actual mercury doesn’t reach that level. Senior meteorologist Jim Dale from British Weather Services noted the impact of the heat dome and influx of hot air from neighboring regions, underscoring the importance of humidity in amplifying the heat index and making temperatures feel significantly hotter.