As temperatures in the UK edge towards 37C, the Met Office has issued an amber extreme heat warning covering vast swathes of England and Wales – only the sixth such warning since the system was introduced in 2021. The warning signals that the coming heatwave poses a real risk to health and infrastructure, and it has prompted the UK Health Security Agency to issue its own amber heat health alerts for parts of England.
An amber extreme heat warning is the Met Office’s second-highest alert level. It means there are likely to be “widespread impacts on people and infrastructure”, including adverse health effects for the wider population, disruption to travel, and potential power cuts due to “heat-sensitive systems and equipment” failing. The warning came into force at 1am on Monday 22 June 2026 and runs until 11.59pm on Tuesday 23 June, covering London, the east and south-east of England, parts of the south-west of England, the Midlands, and areas of Wales.
“Explains the UK's amber extreme heat warning, heatwave criteria, health risks, and what to expect.”
For a hot spell to officially become a heatwave in the UK, temperatures must exceed a certain threshold – which varies from 25C to 28C across different parts of the country – for three consecutive days. While a slightly cooler Saturday meant nowhere had yet met that criteria, the Met Office expects the threshold to be met over the weekend and into early next week, particularly in parts of England and Wales. Temperatures are predicted to peak around 35C or 36C on Monday and Tuesday in southern England, with a good chance that the UK’s June temperature record of 35.6C (recorded in Southampton in 1976) could be broken. By Wednesday, values as high as 37C are possible. Overnight, some locations will experience “tropical nights” where the temperature does not drop below 20C.
The heatwave is part of a wider pattern across Western Europe, where an intense hot spell – driven by human-induced climate change – is affecting much of the continent. In France, temperatures could reach 42C, and half the population is under a severe weather warning. The Met Office’s deputy chief forecaster, Greg Wolverson, said that while heatwave criteria will be met for some in the south and south-east of England over the weekend, the warmth will expand and intensify at the start of next week, with high humidity making conditions feel “close, warmer and more uncomfortable”.
For UK readers, the practical impacts are significant. The amber warning advises that people vulnerable to extreme heat – including the elderly, young children, and those with pre-existing health conditions – face increased risk. The UK Health Security Agency has issued amber heat health alerts for the east, south-east and south-west of England, as well as London, until 8pm on Tuesday. Travel disruption is possible, and the Met Office has warned that power cuts could occur. High UV and pollen levels are also anticipated in many places. The hot, humid conditions may bring isolated thunderstorms and downpours on Monday and Tuesday, but these are expected to be fairly localised.
Q: How long will the heatwave last? The amber warning covers Monday and Tuesday, but high temperatures are expected to continue into Wednesday, with 37C possible. The hot spell could see some locations above 30C for six or seven consecutive days, with very warm overnight temperatures.
Q: What is the difference between an amber heat warning and a heat health alert? The Met Office issues weather warnings (amber, yellow, red) based on the expected impact of the weather. The UK Health Security Agency issues separate heat health alerts that focus on the health risks to the population. Both are in effect at the same time during this heatwave.
Q: Is this heatwave linked to climate change? The Met Office has stated that the increasing frequency and intensity of heatwaves globally is consistent with predictions for human-induced climate change. The current hot spell spreading north from France is part of that trend.
What happens next depends on how the weather evolves. The Met Office will continue to monitor temperatures and may update or extend the warning if necessary. The June temperature record could be broken on Tuesday or Wednesday. Meanwhile, the UKHSA’s heat health alerts remain in force until Tuesday evening. For now, the advice is to stay cool, stay hydrated, and check on vulnerable friends and relatives.