The UK has provisionally recorded its hottest day of the year, with this week expected to be the longest prolonged period of hot weather ever seen in September, the Met Office has said. Temperatures reached 32.6C (90.7F) in Wisley in Surrey on Thursday, the Met Office said. Amber heat-health alerts are in place for much of England, with only the north-east under a yellow alert. The Met Office said that while temperatures had reached similar levels in 2020 and 2021, hot weather this week could last until the end of the weekend. Thursday was the third day of temperatures over 30C – which already matches the previous record for consecutive days of high heat in September. Experts said the extreme temperatures should be a wake-up call to international leaders to rapidly reduce carbon emissions, after analysis by Climate Central said that the current heatwave forecast in the UK was made five times more likely by the climate crisis. Forecasts indicate that temperatures in cities including London, Leicester, Leeds and Birmingham will be more than 10C higher than the 1991 to 2020 average for this week, the analysts said. More than 61,000 people died in the European heatwaves of 2022, according to a recent study, including more than 3,000 in the UK. Heatwave conditions were already met in areas of West Yorkshire, Cornwall, Devon and Wales on Tuesday, according to the Met Office, but the temperature did not surpass June’s highest temperature of 32.2C. Health warnings have been put out across the UK, and the NHS is expected to come under extra pressure as a result of the heat. More than half of councils this year have made preparations to stop road surfaces from melting by treating them with sand, said David Fothergill, chairman of the Local Government Association’s community wellbeing board. He urged people to take care in the hot weather. “Some people are more at risk of harm from high temperatures and need to be more careful. These include older people, especially those over 75, people who live on their own, those with a pre-existing health condition, babies and young children and people who spend a lot of time outside,” he said. Simon Partridge, a forecaster at the Met Office, said current temperatures were not unusual in September, but said the hottest day of the year did not often happen this month. “The fact that we are getting the hottest day of the year in September this year is more a reflection of how much cooler July and August were this year,” he said. But he remarked that the longevity of the hot weather had not been recorded before. “It does look like a fairly safe bet that by Sunday we will have had temperatures above 30C for six days, previously the longest we have seen that level of heat is three days,” he said. Temperatures are expected to begin to fall at the weekend, with a chance of thunderstorms on Sunday, said Partridge. Asked why the Met Office was had called Thursday’s hottest temperature “provisional”, he said that – as well as being standard practice – it was a sensible measure to take. One year a provisional hottest temperature had been recorded, but CCTV footage later revealed that an ice-cream van had been parked by the weather enclosure, and it is believed heat from its exhaust pipe had tipped the temperature to the record level. “That’s why we always say provisional,” he said. “There’s always the ice-cream van factor to bear in mind.”