I suspect it's not just the cloud cover. Looking at the map, it's quite depressing to note just how high up north even London really is. Berlin, Warsaw and Amst

I suspect it's not just the cloud cover. Looking at the map, it's quite depressing to note just how high up north even London really is. Berlin, Warsaw and Amsterdam are all similarly positioned. If we pan west along the 50° north parallel, the first reasonably large city in the American continent is ... Winnipeg. We just don't get that much sunlight throughout the year to start with.