UK heatwave triggers 'false autumn' as trees shed leaves early

Experts say two thirds of Europe is under drought alert and dry conditions will remain until November

A man sits on a deckchair among brown leaves fallen from the trees in St James's Park, central London, on Wednesday. AFP

With a prolonged spell of hot and dry weather, a “false autumn” has set in across parts of the UK, as the summer's record-breaking temperatures led some trees to shed their leaves early.

Many parks and gardens are already carpeted in a sea of golden-coloured leaves, weeks before autumn officially begins.

Experts said the early fall is a sign of stress, as trees attempt to retain moisture amid the soaring heat and low rainfall.

The UK last month issued its first red warning for extreme heat as the temperature hit 40.3ºC, the highest in the country since records began.

"The trees are enacting the hormones they use in autumn to just retract and ensure their survival," said Rosie Walker of the Woodland Trust conservation charity.

"They'll keep going like this for a few years but it is going to start impacting our trees if we're not very careful," she told BBC radio.

Fallen leaves are most likely to be from birch, silver birch and rowans.

"We saw the first turn in silver birch on August 12, which is incredibly early," said Ms Walker. Other species were also shedding their leaves, she said.

The Trust also recorded the earliest appearance of ripe wild blackberries, which normally appear in autumn, on June 28 this summer.

It issued a warning of the potential effect the early ripening could have on small mammals and birds who store energy in September and October for the cold winter months.

"Nature's timing is everything for our wildlife," said Steve Hussey, from the Devon Wildlife Trust in south-west England.

"The climate crisis is bringing with it seasonal weather patterns, which our wildlife is just not adapted to.

"Our long, hot summer and the false autumn will have a knock-on for many species right into the real autumn months and beyond."

Animals such as dormice, which consume high-fat foods such as hazelnuts and other hedgerow fruits in autumn, could struggle to feed if these are gone by the end of this month, said the Trust.

The Met Office has issued a warning of more 40ºC days due to climate change, with extreme heatwaves 10 times more likely to happen in the UK due to the rising global temperature.

Almost two thirds of Europe is currently in a state of drought alert, a recent European Union report said, and the problem is expected to persist for several months.

The European Drought Observatory, overseen by the European Commission, said 47 per cent of Europe was under “warning conditions,” with “clear deficit of soil moisture”, and 17 per cent in a state of alert, affecting vegetation.

"The severe drought affecting many regions of Europe since the beginning of the year has been further expanding and worsening as of early August," said the report.

The western Europe-Mediterranean region is likely to experience warmer and drier-than-normal conditions until November, it said.