So it looks like this year will see October more than 2C above average and November possibly more than 1C below average.
This combination has only happened twice before since 1900.
1969/1970 is an interesting comparison. In that year December was cold at 3.3C (nearly 2C below average but obviously nowhere near as cold as 2010). January was a little below average at 3.7C and February well below at 2.9C. What is particularly interesting is how cold the following March and April were at 3.7C and 6.7C.
The other similar year is 1921/22. November was colder than this year at 4.6C and December turned out very mild at 6.5C. The rest of the winter was unremarkable and fairly average with January at 3.7C and February at 4.4C. But again March and April were very cold with 4.6C and 5.5C.
A set of two data points is not exactly enough to draw any strong messages from but there is certainly a precedent for the type of set up we have had this Autumn to produce a very late start to Spring with very cold weather potentially persisting through most of April. Will be interesting to see what happens.