In article ,
Ian Bingham writes:
Thanks for these figures, John. Very interesting. What strikes me
about them though is how un-smooth they are for an average of 235
years. For example, in the second half of February the temperature
rises from 3.73 to 4.45 in just 3 days. This rather suggests that the
winter temperature profile has changed during that period, and probably
several times. For example it changed after Buchan's time, resulting
in the poor fellow getting an undeserved raspberry from the
meteorological cognoscenti.

Yes, I'm sure that there must have been changes. I'm going to try
looking at the last hundred years or so, and see what difference that
makes. (I think that a 30 year period, though fine when looking at
monthly means, would be too short for daily means, as there's a greater
possible range of daily values than there is for monthly ones.)

My 21-year mean temperature falls throughout December to a minimum in
the week between Christmas and the New Year, rises to the mid-January
maximum, then falls to the last week of January. It then rises to the
6th of February, after which comes a cold period from the 8th to the
19th which, as you say, roughly corresponds to Buchan's First Cold
Spell, but overshoots it by 5 days.

So what you see for December and February sounds broadly similar to what
I've found for the period since 1772, but very different for January.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)