But in the winter the 'north' gets the cold, ice days, below average temps, and snow. Meanwhile down here in the 'south' its normally mild & frost free let alone below average. It would seem it's far easier for the south to be above average in both summer & winter whilst reversely the north finds it easier to be below.
In the winter the north's long term average is colder. Is there is evidence that month's are more likely to be even further below the average value? This would suggests that the winters are getting colder up here compared with the WMO climate means. (Of course it will usually be colder than further south, that's the climate).
If the north normally got colder than average for a certain season or the south normally gets warmer than average surely that shows that the averages are incorrect? Do you think that is the case. On average any area should over a period of time average out at the mean unless the climate has changed?
We all know (presumably) that the average for the south is higher than that of the north, so that is a moot point and not what is being discussed. Some don't like it I realise that but it doesn't change the validity of discussing it. This is why my comments on temperatures are not N v S in isolation but conparison with the long term averages for the locality.