In article ,
Gavin Staples writes:
As many will be aware, it is 18 years since the great cold spell of January
1987 which delivered daytime maximums below -5C.
I had -8C and I believe that a maximum of -9.1C was recorded in Surrey
or Sussex. Apparently this spell delivered the coldest 48 hour period in
Britain since 1740.

The Weather Log for the month says cautiously: "...it seems likely that
it was one of the coldest spells of weather in the south since January
1740..."
--
John Hall
"The power of accurate observation is commonly called cynicism
by those who have not got it."
George Bernard Shaw