digitS' wrote: I live where the "low" is the lowest. Here it is farther north than the northern most point in Maine, so there are few hours of winter sunlight and the angle of sunlight is low. Still, the winters are not as likely to be as severe as much of Maine and certainly not as severe as much of the interior of the continent.
Another family moved to Eastport, Idaho, at the same time as mine, way back in the 1960s. They left the following year. The wife couldn't take it, because there just wasn't any sun. She said the lack of sunlight was making her crazy. I remember we used to board the schoolbus in the morning when it was pitch black outside and disembark in the afternoon when it was pitch black outside. During the winter, we saw daylight at home only on the weekends and holidays.
That chart of yours was interesting! Wyoming was only behind NM, AZ, TX, CA, and HI for highest average sunlight. I suspect that's because we are rarely cloudy up here, and, in my area, there is just one mountain, Casper Mountain, to block the sun.
I wouldn't recommend it for greenhouse growing, though. Yesterday we had all the precips: rain, hail, sleet, and snow. The day before, we had tree-bending winds. It would take a sturdy greenhouse to survive the elements up here