Following several weeks of drought across the United Kingdom, recent shifts in weather have brought thunderstorms and rain showers to many regions. However, the accompanying rise in humidity has led to increased discomfort, with many reporting sticky clothing and clammy skin.
Relative humidity levels have climbed significantly, reaching as high as 85 percent in some areas. This change is attributed to a developing low pressure system over Spain, which has directed warm, moist air from the Atlantic Ocean northward toward the UK. This southerly airflow is warmer than the previous conditions dominated by stable high pressure systems, allowing the air to carry greater amounts of moisture.
Humidity plays a critical role in how the body regulates temperature during summer heat. Normally, the body cools itself through the evaporation of sweat. When humidity is high, this evaporation process is impaired, reducing the body’s ability to cool down effectively. According to Dr. Akshay Deoras, a meteorologist at the University of Reading, damp clothing and a clammy sensation result from the reduced evaporation, which also diminishes the cooling benefits of sweating.
The impaired cooling mechanism can lead to a higher risk of dehydration, as the body continues to produce sweat in an attempt to lower its temperature. Deoras warned that this could escalate to heat exhaustion or heat stroke in severe cases. He emphasized the importance of taking protective measures against overheating, including using fans and keeping curtains closed to reduce indoor temperatures, even when sunlight is less intense than in previous weeks.
Beyond physical discomfort, elevated humidity can affect respiratory health. High moisture levels in the air may increase the difficulty of breathing and can provoke asthma attacks or worsen chronic obstructive pulmonary disease (COPD).
Research conducted at the University of Bath indicates that humidity also impacts cognitive performance. In controlled experiments at 27°C, participants tested under 70 percent humidity showed declines in memory and attention capabilities, with productivity dropping by as much as 20 percent. Dr. Sharareh Azar, a sustainability engineer involved in the study, noted that the sensation of heat and discomfort likely contributed to increased mental workload, making tasks feel more demanding.
Looking ahead, weather conditions are expected to remain variable, with ongoing bands of rain particularly affecting the northeast of the UK. The Met Office forecasts that winds may strengthen over the weekend, potentially easing the oppressive feeling of the current humid air mass.