The image below shows typical UK late December weather, Atlantic low, continental high, drifting snow and night-time frost especially in Northern England and Scotland. Indeed the UK has had something like a proper winter December all moth.
The weird thing is that it is the normal from thirty years ago. In recent years our winter has been confined to a few days in January and maybe a late one day blast in March. These days the new normal is a December when we watch green stuff still growing when it shouldn't.