Cold Arctic air is set to sweep across the UK as communities in Wales recover from severe flooding that inundated properties and disrupted transport and power networks.

Storm Claudia moved away on Sunday after delivering over a month’s worth of rain to parts of England and Wales during the weekend.

It will leave beind drier, calmer, and significantly colder weather. Snow is possible on higher ground in the northern half of the UK by Tuesday.

The cold snap comes as people rally together to help residents and business owners recover from unprecedented flooding in Monmouth, Wales.

A major incident was declared in the town by South Wales Fire and Rescue Service on Saturday morning as crews helped dozens of people to safety.

Natural Resources Wales (NRW) has issued four severe flood warnings in Monmouth amid concern of a “significant risk to life”. The River Monnow has reached record levels – exceeding those recorded during Storm Dennis in 2020 and Storm Bert in 2024.

The major incident declaration will remain in place until power is restored, fire authorities said. Disruptions on rail services in England and Wales are also likely to linger into Sunday afternoon.

While that low pressure system has been replaced by mostly calm and dry weather, Sunday and Monday could bring a few wintry showers on exposed eastern coasts.

Highs of 5–10°C are expected across much of the UK in the coming days.

By Tuesday, low pressure brings rain and sleet, with snow possible on higher ground in the northern half of the UK.

Midweek stays cold with brisk northerly winds, and sleet and snow showers are likely, mainly along northern and eastern coasts, as well as Northern Ireland, west Wales, and possibly the moors of south-west England.

The significant drop in temperature is due to a change in wind direction.

Since the start of this month, there has generally been a southerly wind bringing a very mild, but cloudy, tropical maritime airmass all the way from the Canary Islands.

This pattern will change. After being on the warmer side of the jet stream, the UK will be on the colder side of it.

Major flooding in Monmouth saw people rescued from their homes. Some had to be evacuated to a nearby library.

Monmouthshire MP Catherine Fookes said it was a “really worrying time” for residents and businesses” and while the “big clear up” continued, its existing flood defences would need to be reconsidered.

“This community is incredibly resilient and kind,” Fookes said.

The town’s fire and rescue service said hundreds of homes had been left without power.

Flooding has been less severe in England, but an ongoing risk remains, with 42 flood warnings in place.

The weather has also triggered major disruption on rail networks.

All lines were blocked between Swindon and Bristol Parkway on Sunday morning, Great Western Railway said, with services impacted between London Paddington and Swansea. The disruption is expected to last until midday.

National Rail has warned passengers to check before they travel and the AA told drivers to avoid travelling in “hazardous weather”.

Additional reporting by Nicholas Bourne