Has this country at any given time experienced complete dry weather from border to border and coast to coast.
It would be almost unimaginable that a precipitation-free period might occur across the 48 contiguous states for even a few hours, let along an entire day. It’s probably never occurred, although records of such events are not kept. While there are times of the year when precipitation is at a minimum, like the late September into October when high pressure dominates, there would still be some “orographic-lift” showers caused by air moving up a mountain side. Even in tranquil weather situations, drizzle can occur in foggy areas and in winter when large arctic high pressure dominates the nation, lake-effect rain and snow showers will form down wind of the Great Lakes and other bodies of water.