Wales is set to endure some of the hottest weather ever recorded in June, with forecasters warning that temperatures could reach 35°C in south-east Wales as an intense heatwave grips the UK this week.
The Met Office has extended its Amber Extreme Heat Warning from Monday through to Thursday, with temperatures expected to rise rapidly at the start of the week before peaking on Wednesday and Thursday.
While southern parts of England could see highs of 38°C, temperatures in south-east Wales are forecast to reach around 35°C on Tuesday, bringing potentially dangerous conditions and widespread impacts.
Forecasters say the combination of extreme heat and unusually high humidity will make conditions feel particularly oppressive, increasing the risk of heat-related illness across the population.
The Met Office said temperatures will climb to around 34°C in southern England on Monday before rising further to 37°C on Tuesday. The heatwave is then expected to intensify, with temperatures potentially reaching 38°C during the middle of the week.
Met Office Deputy Chief Forecaster Tom Crabtree said:
“The forecast heatwave is developing into an impactful severe weather event, with record breaking June temperatures and very high humidity. The combination of heat and humidity will be oppressive and bring impacts across society from public health and infrastructure, to power and water supplies.
“As well as very high daytime temperatures, there will be consecutive nights where temperatures do not drop below 20°C, which is called a Tropical Night. This will make it very hard for people to recover from the daytime heat, exacerbating the heat stress impacts.”
The Met Office says widespread “tropical nights” are expected across southern parts of the UK, where overnight temperatures remain above 20°C. Such conditions can significantly increase heat stress by preventing buildings and people from cooling down overnight.
Humidity levels are also expected to be exceptionally high. Dew points, which measure moisture in the air, are forecast to reach around 22°C on Wednesday and Thursday. By comparison, dew points during the record-breaking July 2022 heatwave were only in single figures, highlighting how uncomfortable conditions could become.
The heatwave is now expected to challenge the UK’s June temperature record of 35.6°C, which was recorded in Southampton in 1976 and at Camden Square in London in 1957.
The Amber warning highlights the potential for adverse health effects not only among vulnerable groups but also across the wider population. It also warns of possible disruption to transport networks and pressure on energy and water supplies.
Officials are also urging people to take care around rivers, lakes and coastal areas, with warmer weather likely to encourage more people to seek relief near water. This raises the risk of water-related incidents.
The UK Health Security Agency has also issued Yellow and Amber Heat Health Alerts, warning of increased pressures on health and social care services.
Although the week will be dominated by hot weather, there remains a risk of isolated thundery downpours on Monday and Tuesday.
The most extreme temperatures are expected further south and east across the UK, while north-western areas are likely to remain closer to average for the time of year and see more unsettled conditions later in the week.
Residents across Wales are being advised to stay hydrated, avoid strenuous activity during the hottest parts of the day and check on vulnerable friends, relatives and neighbours as temperatures continue to rise.
