It is yet another hot, sunny day in Cambridge and the cool blue waters of Jesus Green lido have never looked more inviting. Zelna Weich, a 23-year-old PhD student, has just taken her first dip in the water.
“I thought it was going to be much colder than it was. It’s the perfect temperature,” she says, smiling. She is already planning to come back on Monday. “It’s supposed to be, like, 39 degrees.”
In fact, Cambridge is just one of many places in the south of the country where temperatures could exceed 40C (104F).
But local people are used to boiling hot summer days. It was in Cambridge, on 25 July in 2019, that the current highest temperature ever reached in the UK – 38.7C – was recorded, in Cambridge University Botanic Garden (CUBG).
Since then, CUBG has created a “climate change trail” in the garden, which showcases plants likely to be affected by climate change, plants which could be used to help mitigate the impact of the climate emergency, and plants able to cope with the new hot British summers.
Hayley McCulloch, CUBG head of learning, hopes any visitors to the garden during the heatwave will visit the trail to find out more about how the climate emergency is affecting plants all over the world, as well as the work CUBG is doing to support climate emergency research and gardening in a changing climate.
In anticipation of more scorching summers, CUBG gardeners have already been attempting to reduce the amount of watering they need to do, by encouraging plants to form deep roots in the soil.
“We try to leave them for a couple of weeks, if we can, until they have almost dried out – and then we water them very thoroughly again,” Sally Petitt, CUBG head of horticulture, said.
“This process is repeated until they are established. If you instead do regular light watering, the roots tend to form near the surface. These are much more prone to drying out and you end up with very water dependent plants.”
Back at Jesus Green lido, duty manager Chris Green has also been working hard to alleviate the impact of the heatwave, by making sure the freezer is fully stocked with ice-cream. He is expecting record numbers of people to visit the pool on Sunday.
“Throughout the day, we could see maybe 1,000 customers. The water is not heated at all – it’s about 23C at the moment – which makes it that much more refreshing, when you jump in on a hot day.”
The 100-yard pool, which was built in 1923, is one of the longest in Europe and runs parallel to the river Cam on the edge of a large green at the centre of the city.
“Some of our swimmers have been coming here for 50, 60 or even 70 years,” says Green, adding that locals love the lido’s “hidden away” location, which makes it seem so remote from the busy town centre.
“And the length of it means it’s about as close to open water swimming as you can get in a pool.”
Wildlife charity worker Camila Ilsley is planning to take her three children and swim outdoors in the lido and the river Cam today.
“On a hot day, swimming outdoors is fantastic. There’s such a sensation of relief from the heat, and being out in the open air is really exhilarating. It makes us all feel very happy.”
