So I have just been reading about the extremely cold weather of January 1982 and I'm curious about what the pattern of temperatures across a large area looks like under certain conditions. So far as I have been able to gather, on the night when Newport in Shropshire set the English low temperature record of around -26, temperatures across the midlands, where skies were clear anyway, were around minus 15 to 18 in most locations. At my local station in Oxford we reached -16.6, which is our all time low record. What interests me is firstly what factors determine where the extreme cold temperatures are recorded in such conditions--is Newport a notorious frost hollow, or is there a strong element of randomness, in which case Oxford could theoretically reach -20 under a perfect storm of conditions? Extreme low temperature events certainly seem more complicated than 'extreme' high temperature events, where the whole of the SE can be 35c+ away from immediate coastal areas.
Secondly, what is lowest temperature that can feasibly occur in a widespread fashion in England/the UK (I say England because in a mountainous area like the Scottish highlands I imagine it's much much more complex)? Is it, as I assume, around -16 to -18? And how often do these very low temperatures occur--the lowest that has occurred where I live in my lifetime (a mere twenty years) is, I think, about -12, in December 2010, which is an incredible 14 degrees above the all time record for a location with pretty much the same winter averages...
So far as I can tell, a very cold spell, in which temps might reach -10 to -15 across a large area is much more common than an extremely cold one in which they might fall below -15, which might be a once or twice in a lifetime event--and the colder the widespread temperature, the greater the variance, hence the extraordinary reading at Newport. But maybe I'm wrong about some of this. Obviously I am somewhat ignoring urban areas here which seem to struggle even to reach negative double figures at all. I was also fascinated to read that the average daily maximum across many areas in Feb 1947 was as low as -2 to -3--this is like seeing a July averaging over 33 degrees!
Perhaps this is a somewhat perverse subject to think about for those of us in the south today, but I'd welcome any input. And if anyone has done any analysis of these events or has any data on the probability distribution of very low temperatures and the effect of location on this distribution I'd be incredibly excited to see it.
If this is in the wrong forum, mods please feel free to move it.