At present it's a chilly -3.7 C out in my part of the Chiltern Hills. I can vouch for the fact that local un-gritted roads, where the snow has been compacted by vehicles, are quite literally sheets of ice.
If you are driving or walking in the area (or indeed anywhere else experiencing similar conditions), please be very very careful as it is treacherous out there.
Edit: Tuesday morning, 06:30. It is now -7.8 C and has dropped 0.9 of a degree in the last half hour. Brrrrrrr.