In article ,
Gavin Staples writes:
From my area of the UK, which is of course East Anglia. This is how I would
categorise a cold spell. This occurring in either December, January or
February, which of course are the 3 winter months.

1 out 10: 3 or 4 days consecutive, of north westerly winds and night frosts
of -2 to -3. Daytime maximums of between 4 and 5C. The occasional light snow
shower.
snip

Surely you would give the same mark if this weather and these
temperatures occurred with a different wind direction? So should the
wind direction be included in the definition? It might be unusual to get
such conditions with, say, a south-westerly, but it's not completely
unknown ("returning" polar maritime airmass).
--
John Hall

"I am not young enough to know everything."
Oscar Wilde (1854-1900)