Wetter winters continue across the UK
Regions across the UK, from Cornwall to County Down, have experienced their wettest January on record, with heavy rainfall persisting into February. The recent intense rainfall has been attributed to a blocked weather pattern, where a high-pressure system over Scandinavia is preventing the wet weather from moving away.
The Met Office has indicated that wetter winters are likely to become a permanent feature. At current rates of global warming, the frequency of wet winters is expected to increase from once every 80 years to once every 20 years. This shift could have profound effects on housing, transportation, and food supply chains.
One farmer in Somerset told the BBC that he was living on a "knife edge" as his crops were days away from rotting in the floodwater.
Wetter winters more common
On Tuesday, over 100 locations across the UK were under flood warnings, and more than 300 homes had already been inundated, according to the Environment Agency (EA). The persistent heavy rainfall aligns with a pattern observed over recent years of increasingly wet winters. Six of the ten wettest winters since records began nearly 250 years ago have occurred in this century, as reported by the Met Office.
While the UK's rainfall is influenced by natural variability, the trend toward wetter winters aligns with meteorological predictions. The increased combustion of fossil fuels such as coal and oil over the past two centuries has released greenhouse gases like CO2, contributing to global warming.
Although seemingly modest, for every 1°C rise in temperature, the atmosphere can hold 7% more moisture, which can result in heavier rainfall events. Concurrently, sea levels around the UK are rising due to warmer, expanding oceans and melting glaciers. Since 1901, sea levels have increased by 20cm. While this may appear minor, combined with extreme storms and tidal surges, it can worsen coastal flooding.
How much wetter could our winters get?
Currently, the UK experiences about seven days annually with rainfall exceeding 80mm per day, classified as heavy rainfall events. If 30mm of rain falls within an hour, it typically triggers flash flooding warnings.
The Met Office projects that if global temperatures rise by more than 2°C above pre-industrial levels, these heavy rainfall days could increase to nine annually. Despite policies aimed at reducing emissions, the United Nations forecasts a global temperature rise of at least 2.5°C by the end of the century.
In addition to more intense rainfall, precipitation events are becoming more clustered. Prof Lizzie Kendon, head of climate projections at the Met Office, explained:
"That is really important, because that can lead to successive rainfall events, [which] can lead to very saturated soils, and as we're seeing currently in the UK, that can lead to exacerbated flooding as well,"
What is the damage from wetter winters?
Heavy rainfall and saturated soils pose significant risks to homes, transport infrastructure, and food production. In December, the Environment Agency estimated that by 2050, one in four properties in the UK will be at risk of flooding. This assessment is the first by the EA to incorporate the effects of a warming climate on flood risk.
Regions such as the East Midlands, Yorkshire and The Humber, and south-east England are particularly vulnerable. The EA noted that this risk would increase if more homes are constructed on floodplains. The UK government plans to build 1.5 million homes during the current Parliament, with over 10% of new homes in some areas located in flood-prone zones.
The transport network faces similar challenges. Currently, one-third of railways are at risk of flooding, leading to cancellations and infrastructure damage. Government figures project that within 25 years, over half of the rail network will be at risk.
The National Farmers Union (NFU) highlighted the severe risks to agriculture in a letter to MPs in November last year:
"Farmers and growers experience both [drought and floods] on an annual basis, and both severely impact their ability to produce food,"
The wet winter of 2024, the second wettest on record, resulted in £1 billion in losses for the farming sector due to damaged crops.
James Winslade, a beef and arable farmer from Somerset, reported that over 90% of his farm has been submerged in recent rains. He stated he is days away from losing his crops to rot.
"We can't protect everywhere. There isn't insurance for crop damage. We don't get compensation."
He said he is a third-generation farmer, and that his father and grandfather never saw this level and recurrence of flooding.
The UK maintains an extensive network of flood defences managed by various organisations, including farmers, water companies, and charities. Approximately half of the flood defences—around 100,000—are maintained by the Environment Agency, with 9% currently below their target condition. Each defence is rated on a scale of one to five based on its importance.
However, analysis by the BBC Shared Data Unit found that defences not maintained by the EA are 45% more likely to be below target condition.
Increased development exacerbates flooding risks, as impermeable surfaces such as housing and car parks prevent rainwater absorption, causing runoff to overwhelm drains and rivers, potentially breaching flood defences.
An Environment Agency spokesperson told the BBC:
"As a result of climate change, we are seeing more flooding and extreme weather. Whilst it is sadly not possible to stop all flooding, the Environment Agency is committed to helping communities to adapt.
Through the government's flood programme a further £10.5bn [will be] invested in protecting 900,000 more properties by 2036."
With additional reporting from Mark Poynting, Jonah Fisher, Miho Tanaka, and Tom Ingham.
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