The point is that Watertown has had snow in September, and also had snow in June from what Im told - and every month in between. They essentially have a small window in which they have good weather. The rest is overcast/snow. My understanding is that moisture is picked up from lake Ontario and dumped there.
Snow isnt good if its on your solar panels. You can clear it, but its usually overcast when snowing, so a clear panel doesnt operate optimally. It snows a lot there. Its overcast a lot there. Its beautiful country (especially Canton), but isnt solar panel country. Go to Death Valley or the Mojave if youd like an example of good solar country.
Maybe Ithaca doesnt get nearly the snow as the towns in NY state Im familiar with. Thats entirely possible. Still, it seems like a crappy place for solar panels to me.
Every month between September and June, not between June and September... though I wouldn't be surprised.