For some reason weather types occasionally seem to flip over the Christmas period, a cold spell at Christmas can sometimes come to an abrupt end by New Year, and sometimes what looks like a milder Christmas, can suddenly give way to much colder weather as we get into the New Year. Out of curiosity, and with nothing much else to do on a rainy day, I decided to duplicate and refactor my Christmas viewer to produce mean anomalies (or temperatures) from the CETCET Central England Temperature daily series for the periods before (22nd to 28th December), and after (29th December to 4th January) to see what I could find.
As you can see from the results, Christmas 1866 was one of the most schizoSchizo A combining form from the ancient Greek meaning 'I split'. Christmases Central England has seen since 1772, starting mild, with anomalies of +2.1°C, but becoming very cold, with anomalies of -6.5°C into the New Year.
The Christmas of 1796 was another classic, this time starting very cold, with anomalies of -8.1°C, but then turning much milder with anomalies of +1.4°C into the New Year.
The most recent example of a schizo Christmas in Central England was that of 2010, Christmas that year was very cold, with anomalies of -6.8°, but New Year, although still cold was much milder than Christmas, with anomalies of -1.0°C.