UK heatwave alert: Temperatures could hit 38C across London and Southern England

The UK is preparing for one of its most intense June heatwaves on record after the Met Office extended its amber extreme heat warning to four days, with temperatures expected to climb as high as 38C in parts of England this week.Forecasters say the heatwave will build from Monday before peaking on Wednesday and Thursday, bringing not only exceptional daytime temperatures but also uncomfortable humidity and unusually warm nights. The warning now covers large parts of England and Wales, reflecting growing confidence that the hot spell will become a significant weather event with impacts on health, transport, infrastructure and water supplies.The latest forecasts suggest this could be the hottest period of weather seen so far this year and may challenge long-standing June temperature records that have stood for decades.The highest temperatures are expected across southern and eastern England, where thermometers could climb to 34C on Monday, around 37C on Tuesday and potentially reach 38C on Wednesday and Thursday. Some weather models have even indicated a small possibility of temperatures exceeding 40C.

The current UK June temperature record stands at 35.6C, recorded in Southampton in 1976 and Camden Square in London in 1957. Meteorologists say there is increasing confidence that this record could be broken during the coming days.While the most extreme conditions are expected in southern England, temperatures will also climb well above average across much of the country, bringing hot conditions to regions that have so far escaped the worst of this summer's heat.The Met Office has expanded its amber extreme heat warning, which will remain in force from Monday through Thursday. The warning covers much of England and parts of Wales and highlights the likelihood of widespread impacts on daily life.The UK Health Security Agency has also issued heat-health alerts, warning that older people, young children and those with existing health conditions could face increased health risks during the heatwave.Met Office Deputy Chief Forecaster Tom Crabtree described the developing conditions as an "impactful severe weather event", warning that the combination of heat and humidity could place pressure on public services, transport networks, energy systems and water supplies.Authorities advise people to stay hydrated, avoid strenuous activity during the hottest parts of the day and check on vulnerable family members, neighbours and friends.One factor making this heatwave particularly concerning is the lack of overnight relief.Forecasters expect widespread "tropical nights" across southern England, where temperatures may remain above 20C overnight. Such conditions can make sleeping difficult and increase health risks, especially for vulnerable people.Transport operators and local authorities are also preparing for possible disruption.

High temperatures can affect rail infrastructure, roads and public transport services, while increased electricity demand could place additional strain on power networks.Water safety experts have also issued warnings as more people head to beaches, rivers and lakes in search of relief. Previous heatwaves have seen a rise in water-related incidents, prompting renewed calls for caution around open water.Meteorologists say this week's weather event has the potential to enter the record books.The Met Office believes there is a realistic chance of setting a new June temperature record, while some forecasts suggest three consecutive days above 37C, something never previously recorded in June.Climate experts note that extreme heat events are becoming more frequent and more intense. The UK experienced its hottest June on record in 2025, and scientists say climate change is increasing the likelihood of severe heatwaves occurring earlier in the summer.Although temperatures are expected to ease slightly by Friday, many parts of England could still remain in the low 30s, meaning the heat may linger even after the official warning period ends.