Is there any way to "class" different months based on e.g. mean
temperature and precipitation, so you can put it into a certain
category, resulting something like:
January CET:
below:
2°: Chilly
1°: Cold
0°: Unusually cold
-1°: Very cold
-2°: Extremely cold
-3°: Severe
-4°: Exceptional

(Or any synonym of "very very cold" you could find, sorry if I've
might have stolen the examples subconsiously...)
It would be quite interesting, especially with some of the more
exceptional months...
Anyone here who likes the idea?