TL;DR
The Met Office has provisionally recorded 35.1C at Kew Gardens, making it the hottest May day in the UK record. Amber heat-health alerts apply across London, the South East, East Midlands, East of England and West Midlands until 5pm on Thursday.
The Met Office has provisionally recorded 35.1C at Kew Gardens in London during the current spring heatwave, making it the hottest May day in the UK temperature record. Amber heat-health alerts issued by the UK Health Security Agency apply across the South East, East Midlands, East of England, London and West Midlands until 5pm on Thursday.
How the new record was set
The 35.1C reading was logged at Kew Gardens, one of the long-running Met Office observation sites. The reading is described as provisional because it must be quality-checked through the formal verification process before becoming part of the long-term UK climate record.
The previous UK record for May was set during the late May 2024 heatwave, and the May 2026 figure has now provisionally moved past it. The full record dates back to the mid-19th century when systematic temperature observations began across the UK.
Where the heat is concentrated
Highest temperatures have been recorded across south-east England, particularly along the lower Thames Valley and into central London. Heat is amplified by urban surfaces in densely built areas, which is why central London readings are typically higher than the surrounding home counties.
Cardiff, Plymouth, the West Midlands and parts of South West England have also seen unusual late May warmth. Yellow heat-health alerts cover those regions while amber alerts cover the south-eastern half of England.
Why this spell is unusual
Late May heat is not unprecedented in the UK but the combination of duration and peak temperatures is. The current spell follows several days of widespread warmth, with the temperature climbing each day as a stationary high pressure system sat over the UK.
The Met Office attributes the prolonged warmth to a blocking high pressure pattern over north-west Europe. Climate scientists at the Met Office Hadley Centre have noted that the likelihood of extreme heat events in the UK has increased measurably over the past two decades.
Health alerts and what to look out for
The UK Health Security Agency issues heat-health alerts at four levels: green, yellow, amber and red. Amber alerts indicate weather likely to affect the whole population, with rising risk for vulnerable groups including older adults, infants and people with cardiovascular or respiratory conditions.
Symptoms of heat exhaustion include tiredness, dizziness, headache, muscle cramps and rapid pulse. NHS guidance is to move the person to a cool place, get them to drink fluids and cool the skin with a damp cloth. Call 999 if symptoms persist after 30 minutes or progress to heatstroke.
When the heat is expected to break
The Met Office expects the heatwave to peak through Wednesday and Thursday before lower-pressure systems move in from the Atlantic later in the week. Thunderstorms and heavy showers are likely as the heat breaks.
Temperatures are forecast to fall back to the high teens and low twenties from the weekend. The transition can bring intense rainfall in short periods, with surface flooding a possibility in urban areas.
Key facts
- Provisional 35.1C reading at Kew Gardens.
- Amber heat-health alerts apply in five English regions.
- Heatwave peak expected Wednesday and Thursday.
- Heat exhaustion symptoms include dizziness and rapid pulse.
- Thunderstorms forecast as the heat breaks.
FAQ
Where was the new record reading recorded?
Kew Gardens in London logged a provisional 35.1C, the highest May reading in the UK temperature record. The figure must complete the Met Office's quality-check process before becoming part of the long-term climate record.
Which areas are covered by amber heat-health alerts?
London, the South East, East Midlands, East of England and West Midlands. Yellow alerts extend to Cardiff, Plymouth, parts of the West Midlands and South West England.
How long is the heatwave expected to last?
Peak temperatures are forecast through Wednesday and Thursday, with cooler Atlantic air bringing showers and thunderstorms from later in the week. Temperatures are expected to fall back to the high teens and low twenties from the weekend.
What should I do if someone shows signs of heat exhaustion?
Move them to a cool place, get them to drink fluids and cool the skin with a damp cloth or sponge. Call 999 if symptoms persist after 30 minutes or if the person becomes confused, stops sweating or has a high temperature, which can indicate heatstroke.
