Earlier quoted context omitted.
What they don't mention is the length of those seasons, which in Finland consist of winter, winter, winter and construction. Even in Helsinki snow can fall as early as September and as late as May.
It used to be like that, but that's no longer happening. Last winter, there was no snow in Helsinki at all :(
Summer is short enough that there's basically only one growing season for food so that last minute cold-snap really ruined my planting plan!