A heatwave is a prolonged period of hot weather compared to the area’s expected conditions of heat and degree of hotness at that time of year. It may be associated with high humidity.

It is a period of scorching weather that lasts more than two days. Heat waves can occur in the presence or absence of high humidity. They have the potential to cover a large area, potentially exposing a large number of people to dangerous heat. Heat can affect the body and skin. 

Heat Waves in the UK

A heat wave occurs when a specific area has at least three days with daily high temperatures that meet or exceed the average temperature threshold. The threshold varies in the United Kingdom depending on the area.

The danger that the United Kingdom now faces from extreme heat is extraordinary. But this isn’t a one-time incident. Forecasters predict that dangerous heat will become more common in the United States.

Meteorologists expect temperatures around 40°C in the UK for the first time. The country also warns of extreme heat waves. A large part of England experienced extreme heat on Monday and Tuesday. In these days it is reported that temperatures in the high 30s C in some places and possibly exceeding 40° C in others.

This type of heat is increasingly endangering people’s lives. This week, the UK Health Security Agency issued its highest heat health alert. They gave warning that deaths and illness might happen among the fit and healthy rather than just in high-risk groups.

This week, France, Spain, and Portugal are also experiencing extreme heat, fueling wildfires in parts of Europe. However, a typically colder region, such as the United Kingdom, may have even more work to do to adapt to a different type of climate.

The extreme temperatures that we have been forecasting are now beginning to build. On Tuesday, temperatures reached into the high 30s, possibly intimidating the UK record of 38.7°C set in July 2019, said Met Office Chief Meteorologist Neil Armstrong.

For Tuesday, meteorologists report an even higher maximum temperature. With a 70% chance of exceeding 40°C somewhere in England. This level would be 1.3°C or higher above the current UK record.

Record-Breaking Heat

It is the first time in the UK that we have forecast temperatures of 40°C. The current UK’s high temperature is 38.7°C, set on July 25, 2019, at Cambridge Botanic Garden.

Meteorological data models run numerous times to help us measure the likelihood of a specific event occurring and approximate the uncertainty always present to some degree in weather forecasting. 

Some models now predict that maximum temperatures in isolated parts of the UK will exceed 40°C at the start of next week. More widespread temperatures in the mid to high 30s Celsius are expected, with a 95 percent chance of exceeding the current record.

The temperature will return to normal for the time of year, starting in the middle of next week as cool air moves in from the west.

Effect of Climate Change

Temperature extremes have been affecting climate change in the United Kingdom. The likelihood of 40°C days in the UK is ten times greater in the present climate than in a natural environment least affected by human influence. 

The chances of exceeding 40°C anywhere in the UK in a given year have also rapidly increased. Such extreme temperatures could occur every 15 years in the climate of 2100, even with current pledges on emissions reductions.

According to a recent Met Office study, summers with temperatures above 40°C have a return time of 100-300 years. Still, with existing pledges on emissions reductions, this can be reduced to 15 years by 2100.

The chances of seeing 40°C days in the UK are up to ten times higher in the current climate than in a natural environment unaffected by human influence. The likelihood of increasing temperatures up to 40°C in the UK in a given year has also been rapidly growing.

While one °C increase in background temperature may not appear significant, the resulting increase in the severity of extreme heat events is already visible in the observed record. It has far-reaching and effective implications.

Impacts of Heat Wave

Heatwaves are among the most dangerous natural hazards. They rarely get enough attention because the death tolls and destruction are not always apparent. According to reports, almost 166 000 deaths from heat waves between 1998 and 2017. More than 70 000 deaths were reported in Europe during the 2003 heatwave.

Climate change is increasing people’s exposure to heat. Extreme heat is rising in frequency, duration, and significance worldwide. The number of people exposed to heat spells increased by approximately 125 million between 2000 and 2016.

While the effects of heat may aggravate problems in cities, the urban heat island (UHI) effect can also severely disrupt the sources of livelihood and well-being of non-urban communities during and after periods of sweltering weather.

Heat waves can strain health and emergency services, as well as water, energy, and transportation, resulting in power outages or blackouts. These spells may also jeopardize food and sustainable livelihoods. People lose crops or livestock as a result.

Each year, heat waves cause approximately 2,000 additional deaths in England. During a heat wave, staying hydrated, indoors or in the shade, and checking on friends and family is essential.