This explanation doesn't explain why sometimes one says 'L'hiver' and at other times, 'En hiver', and similar for other seasons. The examples given do not enlighten me much. I have always had trouble with this. At first I thought, oh, you use 'l'hiver' when you are going to say something describing a feature of 'hiver', and 'En hiver' when you want to say something happened during 'hiver', but then the other examples given in context of other seasons etc mostly described activities occurring during the season regardless of the 'en' or 'l'' beginning.
I need it stated explicitly what the rule is, there doesn't appear to be one.
