Several people were injured in a multi-vehicle pile-up on the M1 motorway in Derbyshire and had to be cut free from their cars by fire crews.
About half-a-dozen vehicles crashed in heavy rain, blocking the northbound carriageway of the motorway.
In Surrey, a weather alert warned motorists to slow down in 55mph winds.
And in Merseyside five police officers and a man they were trying to arrest were injured when a patrol car collided with them as they struggled in the street.
They were taken to hospital suffering from broken limbs, whiplash and shock.
But it was Wales that was worst affected by the weather, with the RAC reporting that most roads were impassable owing to severe flooding.
Red alerts were issued for several rivers in Wales. Hundreds of acres of farmland became flooded and livestock was trapped on hills. Many sheep have drowned at a critical time for farmers, who expect the lambing season to begin soon.
In one area, 15 bus passengers trapped in their vehicle were saved by a canoeist, who attached a chain to an earth-mover which was able to tow the bus to safety.
Motorists in the region were forced to abandon their vehicles as the A40 became impassable and police struggled to keep Builth Wells open when the River Wye burst its banks. In Brecon, the River Usk broke its banks, flooding more than 100 yards of the town's riverside promenade, while Machynlleth, one of the main towns in Powys, was virtually cut off and several houses were flooded when the River Dovey overflowed.
The region's sport was also affected with the Welsh Grand National at Chepstow, Gwent, being cancelled because the course was flooded.
Travel problems were not confined to roads as InterCity services from Derby to London were delayed by half-an-hour as a result of flooded tracks.
In the South-east, travellers faced delays because of high winds. Force Nine gales forced the cancellation of Hoverspeed and Seacat cross-channel services from Dover.
Elsewhere in Europe it was mild weather that caused problems. Poor snow conditions in Crans-Montana, Switzerland, forced the organisers of the Alpine skiing World Cup to postpone a men's downhill race, but unseasonal weather generally is making it very difficult to reschedule the event.
In London, temperatures yesterday morning were 13C, much higher than the seasonal average. The warm weather is expected to spread to northern regions over the next few days. But the Met Office said yesterday that the new year is expected to begin a few degrees below the seasonal norm.