The UK remains on track for its warmest year since records began, after November became the 11th month in a row of above-average temperatures.
In order not to break the record, temperatures in December would have to drop to almost unprecedented lows, after an average mean temperature of 8.2C over November, the Met Office said.
Although the autumn was overall only the third warmest recorded, according to the official forecaster, the country has not posted above-average temperatures for 11 months in a row since records began in 1884.
During a record-breaking heatwave this summer, temperatures topped 40C for the first time.
“All of the top 10 warmest years on record for the UK have occurred since 2002, a clear indicator of our warming climate,” said Mike Kendon, from the National Climate Information Centre. “Human-induced climate change has increased the likelihood of extreme heat, as we saw in July this year, but this year has also seen persistent warmth, resulting in the year overall challenging the record previously set in 2014.”
The unusual climatic conditions over the past few months, which have also included above-average rainfall, have led to some plants bursting back into life just as they would be expected to enter dormancy.
Dr Kate Lewthwaite, who runs the Nature’s Calendar citizen science project for the Woodland Trust, said she had received reports of a horse chestnut tree in Barnes, south-west London trying to flower again. It was now trying to produce fruit, she said.
Unseasonal flowerings were a sign of environmental stress, Lewthwaite said. “If a tree [experiences] too strong heat, or drought or cold … then a few of the buds that were formed on the tree earlier in the year will burst and attempt to flower.”
Reports of full autumn tinting, where all the leaves on trees have changed to their autumnal yellows and browns, were also continuing to arrive, said Lewthwaite.
Although trees that have had a second flowering or continued growing later in the year may not suffer, continuing mild weather could pose further problems, including the survival of more pests and diseases. High temperatures have led to some insects and animals not yet entering hibernation.
The Met Office said November was the third warmest on record for the UK, with some “exceptionally mild weather” due to a southwesterly flow of tropical maritime air, and some very mild nights, with records set in Scotland and Northern Ireland.
