The UK will face heavy winds, plunging temperatures, icy roads and rain on Monday, forecasters say.
An unseasonably warm autumn has so far helped buffer people from escalating energy costs, but sub-zero temperatures forecast for Monday could leave many confronting the scale of price rises for the first time.
It is expected to be as cold as -4C (24.8F) in parts of the country on Monday morning, with the north-east predicted to be the worst affected.
Peter Smith, the director of policy and advocacy at the fuel poverty charity National Energy Action, said: “The average annual bill has almost doubled since this time last year. So far the milder than usual weather has protected many from the spiralling bills as they haven’t needed to heat their homes as high or as long as usual.
“But as the temperatures fall we know that many people will either start building up unaffordable debt or will ration their energy – or self-disconnect completely. This will have a huge impact on both mental and physical health, especially for those with existing medical conditions. With 6.7m UK households in fuel poverty, this is the start of a bleak winter.”
A yellow wind warning has been issued for parts of south-west England and south Wales from 6am to 6pm on Monday. Gusts of 55mph to 65mph are expected on land and 70mph to 80mph by the sea.
The Met Office meteorologist Alex Burkill said the colder weather would bring a risk of ice and fog, and driving conditions could be difficult.
Burkill said two areas of low pressure were expected to bring very wet and windy weather. The first starts towards the north-west of Northern Ireland and the second is coming up in Ireland and south-west England.
He said that while there was uncertainty around the weather on Monday, there was a risk of strong winds in coastal parts of Cornwall, Devon and south Wales. He said these could affect travel from airports in the region, such as those in Cardiff and Exeter.
While no warning is in place at the moment, Burkill also said there could be significant rain in western areas of Wales and Northern Ireland on Monday.