Environmental groups have warned that Britain’s hottest June on record has caused unusual fish kills in rivers and disturbed insects and plants.
The Wildlife Trust said nature was “being hit by extreme weather without a chance to recover”.
The Meteorological Department will say later on Monday whether the high temperatures are linked to climate change.
Water UK said people also used more water, with demand increasing by 25 per cent at peak times in some areas.
The Bureau of Meteorology said last week that provisional data for June showed that both the overall average and average maximum temperatures were the highest on record.
Mark Owen, from the Angling Trust, told JEE News: “Reports of fish kills in rivers at this time of year are unprecedented. I usually have rivers after summer when it’s hotter and drier. Expect to be impressed.”
In one case, sea trout were found dead on the River Wear in northeast England, he said.
These deaths are partly due to less oxygen in the water as river levels drop. Fish also die when pollution from cars and lorries on roads is washed into rivers during heavy storms.
The Environment Agency said it had received more reports of dead fish than at the same time last year.
Ali Morris from the Wildlife Trust told JEE News that many flowering plants, including orchids, wilt in high temperatures, meaning insects such as bees and butterflies feed on nectar and pollen. They will get less food.
Younger breeds are particularly badly affected. Many butterflies are adults for only a short time, and if they cannot access food during that time, it will stunt the population.
Mrs Morris added that the effects were more surprising given the wet and cold weather and predated last year.
“Every month seems to be the hottest, driest, wettest or whatever record-breaking event. If we have a pollution event or a wildfire, it’s usually nature to bounce back. There is time, but now it seems to be getting faster due to severe weather,” he added.
More frequent and more intense periods of hot weather are putting pressure on the UK’s environment and water supply.
As temperatures rise, people also use more water in their homes. According to Water UK, last July and August water companies supplied 1.2 billion liters more water than in the same months in 2021.
People in Devon, Cornwall and parts of the south-east of England are under a ban on hosepipes.
Water experts say rivers and reservoirs, which provide Britain’s drinking water, are in a healthier state than they were at the same time last year.
But the dry season is likely to affect water supplies, and if the hot weather continues, this supply may run out quickly.
Water UK is urging homes and businesses to “continue to save water to help protect against potential drought conditions in the future”.
Ms Morris points out that people can do their part to help nature cope with the effects of extreme heat by taking small, simple steps.
A bowl of water in the garden or yard can provide water for thirsty hedgehogs, bees and butterflies.
And tall grasses are more resilient in warmer climates and provide much-needed habitat for species, so she recommends allowing even small areas of lawn to grow taller.
