December 1950 was the coldest December since 1890 with a CET of 1.2 but it seems to be largely forgotten these days.
During the month, there were a number of snowfalls and here's a few articles from the Times for that month.
5th of December
It was a pretty snowy month for Manchester, 15cm of snow fell on the 4th December, another 18cm on the 14th and a further 15cm on the 30th.
Manchester
Mean Max: 3.2
Mean Min: -2.6
London Heathrow
Mean Max: 3.7
Mean Min: -0.6
Air frosts: 17
Days with falling sleet/snow: 13
Snow depths for 4th December
Dalwhinnie: 50cm
Houghall: 25cm
Shawbury: 15cm
On the 14th,15th and 16th snow depths include
Shanklin: 37cm
Weymouth 30cm
Ventnor: 28cm
Scarborough: 38cm
Minima for that period 13th-15th December.
Dalwhinnie: -18.3C
Glenlivet: -15C
Manchester: -13C
Snow depths for the 30th
Southport: 23cm
Liverpool: 15cm
From the 15th of December edition and a possible polar low
From the 30th December edition
MANCHESTER SUMMER INDEX for 2021: 238
Timelapses, old weather forecasts and natural phenomena videos can be seen on this site
http://www.youtube.com/channel/UCgrSD1BwFz2feWDTydhpEhQ/playlists