Why this heatwave feels worse than the last one
Why This Heatwave Feels Worse Than the Last One
Why this heatwave feels worse than – This week, England and Wales are bracing for a second heatwave that’s not only breaking June temperature records but also creating a more oppressive experience than previous extreme weather events. While the mercury is set to rise into the mid- to high-30s Celsius, the conditions that accompany these highs—particularly humidity and prolonged warm nights—are making the heat feel even more intense. For example, a forecasted maximum of 35C might feel like 41C, depending on atmospheric factors.
The Role of the Heat Dome
The current heatwave is driven by a powerful, stationary high-pressure system known as a heat dome. According to Dr. Akshay Deoras, a senior research scientist at the University of Reading, this pattern is the “driving force” behind the extreme temperatures. When air descends under a heat dome, it compresses, warming as it reaches the surface. Simultaneously, the air becomes drier, reducing cloud cover and allowing unbroken sunshine to further heat the ground.
“This is not just a heatwave, it is a heat-dome driven furnace that will grip most of the southern UK and push temperatures into truly exceptional territory,” said Dr. Deoras.
Unlike the May heatwave, which centered over the UK and allowed heat to accumulate beneath the high-pressure system, the current dome is positioned over France. This shift has created a south-easterly airflow that carries hotter and moister air into the UK, intensifying humidity and making the heat feel more severe.
Humidity: The Hidden Factor
Humidity plays a critical role in how heat is experienced. While the actual air temperature might hover around 35C, the presence of high moisture levels can elevate the “feels like” temperature to 41C or more. Dr. Deoras highlighted that this phenomenon is due to the way the body regulates temperature. Sweating is a natural cooling mechanism, but when the air is saturated with moisture, the evaporation process is hindered. As a result, the body struggles to dissipate heat effectively.
Weather experts use “feels like” temperatures to account for these combined effects. For instance, even if the air temperature is 35C, the humidity could make it feel as though it’s 41C. This distinction is key, as it explains why this heatwave may have more pronounced health impacts than the one in July 2022, despite similar daytime temperatures.
Record-Breaking Nights and Prolonged Heat
Overnight temperatures are expected to remain stubbornly high, with some locations failing to drop below 20C. These are called “tropical nights,” a term used to describe nights where temperatures stay above the usual summer range. Thursday night may become the warmest June night on record, as minimum temperatures in Wales, the Midlands, and the South East could surpass historical benchmarks. The UK’s record for the highest nighttime temperature is 22.7C, set in 1976, while Wales’ record of 20.3C was recently updated this week.
What makes this heatwave unique is the potential for multiple consecutive tropical nights. In the July 2022 event, while some areas had tropical nights, they were rarely more than two in a row. This week, however, the combination of the heat dome’s position and the moisture-laden air could lead to three or four nights of uninterrupted warmth. Such prolonged exposure prevents the body from cooling down, compounding the effects of daytime heat.
Health Impacts of a Drier, More Humid Heatwave
Although the July 2022 heatwave saw temperatures peak at 40C, it was characterized by dry conditions. In contrast, the current event’s high humidity may result in more significant stress on the human body. Dr. Deoras noted that this combination could increase risks of heat exhaustion, cardiovascular strain, and disrupted sleep. Even healthy individuals may find it challenging to cope with the relentless warmth, as the body’s natural cooling processes are less efficient in humid environments.
For vulnerable populations, such as the elderly or those with chronic illnesses, the effects are even more pronounced. The lack of cooling during the night means their bodies are under continuous strain, raising concerns about long-term health implications. This could also lead to increased hospital admissions and a higher likelihood of dehydration, especially for those without access to air-conditioned spaces.
Living with the Heat: Tips and Challenges
As the planet continues to warm, heatwaves like this are becoming more frequent and intense. The current conditions serve as a warning of what to expect in the future. For now, the focus is on mitigating the effects of extreme heat. Home cooling strategies, such as using fans, closing blinds, and staying hydrated, are essential. Meanwhile, questions about whether to keep children off school or suspend work during the heatwave are gaining attention, as prolonged exposure to high temperatures poses risks to productivity and well-being.
Experts emphasize that while the “feels like” temperatures may not always match the actual readings, they provide a clearer picture of how the heat impacts daily life. With the possibility of multiple tropical nights, the UK is facing a more sustained and uncomfortable heatwave, one that could test the limits of both infrastructure and human resilience.
The combination of record-breaking temperatures, persistent humidity, and the emergence of tropical nights underscores the complexity of this year’s heatwave. Unlike past events, where the heat was more intermittent, this prolonged period of extreme conditions is likely to leave a lasting impression on the public. As the weather continues to evolve, understanding the factors that contribute to the “feels like” effect becomes increasingly important for preparing for future heatwaves.