Leaves falling, berries ripe, but it's hot. Is autumn coming early? 4 days ago Share Save Georgina Rannard Climate and science correspondent Share Save Tim Dodd/BBC Puppies have enjoyed the leaf fall in Cardiff in August Share Save Tony Jolliffe Climate and science team Share Save It's still hot in many parts of the UK, but some tree leaves are turning yellow and blackberries are so ripe in hedges that they're tasting alcoholic. Councils in London have issued "do not sit under trees" warnings because of the dangers of dying branches suddenly falling. What's going on? Is it still summer, or has autumn started already? And does it matter anyway? There is no formal definition of "early autumn" but experts say signs of the season, like leaves falling or apples being ready to pick, are actually nature becoming stressed by the long hot and dry summer. And a potentially historic one at that - the Met Office says this summer is on track to be one of the warmest since records began in 1884. Berries, some of which are usually ready in the autumn, have ripened in late July and August - and many have seen a bumper crop In Cardiff, Wanda O'Connor has grown melons outside for the first time since she started growing food six years ago. She shows me ripening limes and lemons inside her allotment greenhouse. "It's 38-39C in here," she says, pointing to a thermometer. Aubergines, red peppers, courgettes and lots of tomatoes have all thrived in the above-average temperatures and extra sunshine hours. At the same time, classic autumn fruits like blackberries and apples - normally ready in September - are hanging off the branches. Conservationists are still gathering data about whether this is record-breaking. Blackberries were seen in London on 22 June, according to the Woodland Trust. By contrast the earliest in 2024 was 4 July in Southampton - but scientists need more information to be certain about the long-term trend. For Wanda in Cardiff, this has meant more food to take home for dinner, but it's harder work than usual for her to water her plants. Wanda O'Connor has grown food at Pontcanna allotments in Cardiff for six years "In a normal year I'd come every three days, but this year it's every day. If I don't, the plants will die," she explains. Farmers across the UK have, too, seen early harvests with some crops struggling in the heat, prompting concerns about food prices. Last month, the Environment Agency said North West England, Yorkshire, the East Midlands and West Midlands were in drought. Parts of Wales, including the Cardiff area, have had the driest six months since 1976 and are in drought as well. The ground is dry in large parts of the UK, including at this allotment in Cardiff The UK has had 71% of the average rainfall for the season so far when it should be 79% by this date, according to the Met Office. And we've had 89% of the average sunshine hours for summer. The Met Office says we would expect 79% by this point. Climate change is affecting the timings of biological events including spring and autumn, according to the Met Office, although the level of change varies year-to-year. At the Botanical Garden of Wales in Carmarthenshire, Luke Cheesman is having to work harder than usual to keep the garden healthy and attractive for visitors. He's seen signs of stress like tree leaves turning yellow and falling, and branches drooping - so alongside extra water, he's mulching trees and adding organic material on top of the soil to keep it moist. He says this is good advice for those with plants or trees suffering at home. Luke Cheesman looks after almost 600 acres in the National Botanic Garden of Wales "We've had three almost back-to-back heatwaves. It's not giving the trees much chance to recover," he says. It's a similar story at Kew Gardens in London, where head of tree collections Kevin Walker says the last drought in 2022 killed nearly 460 of his trees - and he's seeing the same stress again. English oaks are losing leaves on the canopy and producing deadwood, he says, and Norway Maple and magnolias are showing signs of stress. Getty Images The leaves of a Norway Maple tree in a file photo "They're throwing their leaves, and will try and sit it out till next year," he says, while "summer branch drop" - where trees try to save energy by losing branches - is also happening which can be dangerous to people nearby. "It's a live fast, die young strategy. That may work for a one in 10 year event. But instead of a drought or stress period being a one-in-10 year event, it's becoming a one in every two or three years," he says. Tim Dodd/BBC News Leaves are lining the paths in Cardiff's Bute Park