| Meteorologically speaking, summer started on 1 June. “But you wouldn’t necessarily know it,” Bentley says. “It has been exceptionally, unseasonably cold and – unfortunately – the forecast suggests it’s going to stay that way.” Bentley reckons that today temperatures across the UK will range around 11-16 C. “At this time of year, temperatures should range from 17-21C so that’s a good five degrees below normal. It’s not just perception, it is noticeably cooler.” It has been, Bentley says, consistently cooler than average throughout June, and is likely to stay that way until at least astronomical summer begins with the summer solstice on 20 June. Today could be the best day for a little while with no rain forecast, before another band of rain sweeps across on Thursday. “The weekend looks showery, and the temperature will be well below normal right into next week,” she says. “Even through to the end of the month looks very unsettled, all eyes are now on July until we might see a taste of summer.” Why is it colder than normal in the UK? It’s all to do with the jet stream – defined by the Met Office as “a core of strong winds about five to seven miles above the Earth’s surface, blowing from west to east”. “At the moment we have northerly flow of air all the way from the Arctic,” Bentley says. “Even in June the Arctic is a lot colder, and if you’re out and about you will notice it’s very cold. The wind can be quite bitingly cold, making you want to wear scarf and gloves. However, if you get out of the wind and in the sun is shining it does feel quite pleasant.” The jet stream has been “buckled” over the UK, says Nick Lee, a meteorologist at MetDesk, a private company that provides “mission-critical weather information” to weather-dependent businesses. “It has become quite entrenched and is dragging cold air from the Arctic down across the UK, making it cold here particularly at night,” Lee says. “If we were just the other side of it would be much warmer, as it would bring the warm air from Africa.” The other side of the jet stream is basking in unseasonably warm temperatures. To the west: New York is expecting temperatures of 28C today, and to the south: Greek authorities have issued heatwave warning forecasting temperatures to rise to as much as 42C. Is it really snowing in June? While no cricket matches have been snowed-off this summer, the Cairngorm mountains in Scotland were covered in a light dusting of snow last week. The Met Office has recorded temperatures of –2 C at the top of the mountain on 4 June, compared to average June temperatures of 13-16 C. Snow in June is very unusual, but in 2010 more than 100 skiers took advantage of ski tows being open up at a ski resort near Aviemore for the first time in summer. Lee says night-time temperatures have been much colder than daytime, and the mercury has dipped below zero in rural places across the country. “As far south as Oxfordshire it got as low as 1C recorded at RAF Benson [near Wallingford, in South Oxfordshire] on Sunday.” He reckons that the UK could have just witnessed its “coldest run of nights in more than a decade”, but he wouldn’t bet on the record holding out for the whole of June. But haven’t we just had a record-breakingly warm May? Yes, the UK’s average mean temperature in May 2024 was 13.1C, beating the previous 12.1 C set in 2008 to take the highest May average since records began in 1884, according to the Met Office. But, you might not have noticed, because the averages were brought up by exceptional warm overnight temperatures caused by greater cloud cover. The northern half of the UK experienced an even hotter May, with Scotland recording a mean temperature of 12.3 C, beating 2018’s previous record by 1.6 C. Does it just feel colder now, because it has been warmer? “This time last year it was 30C in the south [of England], well above the 20-21 average for this time of year,” Bentley says. “So comparisons to that definitely make a difference. “But it is not just perception, it definitely is colder than normal. We are five degrees below where it should be, so it’s not only that it feels cold – it is cold.” It’s true, she says, that Britons will complain about the weather whatever temperature it is. “I bet you that this time last year people were complaining it was too hot,” she says. “There seems to be a threshold of 27 C: below that it’s pleasant, above that it starts to become too hot and people start to suffer – and let you know.” Why are temperatures low if we’re in a crisis of global heating? Temperatures vary throughout history, Bentley says, and a colder than expected June does not mean that overall temperatures aren’t rising. “If you look over the longer period, a decade, or three decades [from which meteorologist take the expected averages] you’ll see that temperatures are increasing steadily.” It’s not just temperatures that are affected by global heating. “We do focus on temperatures, but climate change is much more about how weather patterns are changing,” she says. “For example, we know that a warmer climate, can hold more moisture, so when it rains it tends to be heavier. We get heavier rainfall in the UK in winter and spring. “There’s more extreme weather across the world. There’s extreme heat in India right now, and we’ve seen flooding in Germany and France recently.” It’s a worrying time to be a meteorologist, says Bentley, who first got interested in the weather when as a child her mother accidentally left her in the back garden of their Huddersfield home when “she thought it was a beautiful summer’s afternoon” but “within half an hour the sky went black and there was hail the size of golf balls”. “It’s quite scary, when you see these records being broken – it’s quite a stark message: Our climate is changing and changing rapidly.” Bentley was this week one of 408 climate scientists who wrote an open letter to all the UK party leaders urging them to “pledge ambitious action on climate change”. If she had five minutes with the next PM, Bentley would say: “We know what the problem is – we are burning too many fossil fuels, – and we know what the solution is – stop it. The lack of action is quite frustrating.” | 