October 2001 didn't feel remarkable and that was the record !!
Chiefly because it was pretty miserable in many respects other than temp being dull and wet with some flooding at times too...
Back in those days there were no monthly CET comps and I remember being quite surprised a few days before the end of the month when the news announced we were closing on a record .
I think it was the mild nights that really marked it out from other warm editions.
We then had 2 clones in quick succession in 2005 and 2006 which normalised the mild dull and wet October as something of a trope... Give me a cold sunny 2003 any day over that