Travellers are being warned to expect disruption as snow and ice is forecast across large parts of the UK on Wednesday night and Thursday.
The Met Office said wintry conditions, freezing showers and icy patches could lengthen journey times and cause falls.
The first snow and ice warning from 22:00 GMT covers western parts of Scotland, Northern Ireland, north Wales and northern England.
Thursday’s snow warning extends through the Midlands and towards London.
Some roads and railways are likely to be impacted by snow and ice overnight in northern parts of England, western Scotland and Northern Ireland, the Met Office said.
It said there would be less disruption in southern parts than elsewhere on Thursday, but still predicted sleet and snow could cause some travel disruption.
Councils across England have placed highways teams on standby with an estimated 1.5 million tonnes of salt on hand to cope with any icy conditions.
The Local Government Association said local authorities were reminding residents to check on elderly neighbours and relatives.
BBC Weather presenter Matt Taylor said parts of the Midlands and southern England could see their first snowfall of winter on Thursday.
He said any fall of rain or snow was going to be unwelcome for those communities suffering from flooding.
“Every single drop we do not need,” he said. “There is the potential for river levels to rise again.”
It came as people evacuated homes and businesses after flood waters rose above defensive barriers in Worcestershire.
There are also two severe flood warnings in place in Shropshire, with the River Severn at risk of breaching its defences in Ironbridge.