I was doing the CaP for today and found a notice about something called New England’s Dark Day. As explained in the link this was most likely caused by a combination of heavy cloud cover, fog and smoke from forest fires all at the same time. It also tells that the darkness was such that candles needed to be lit in order to see properly.

I haven’t thought through how a meteorological phenomenon like this would occur but it could be an interesting plot device and so should not be completely unheard of. This kind of event should be reliably predictable by meteorology.