What areas in North America are strongly affected by cloud cover?  The main controls on cloudiness are:

synoptic variability from day-to-day

topographic effects

diurnal effects

land albedo gradients, most importantly the sea-land breeze contrast

 

Sky islands in US/Mexico

California coastal cloudiness and rain shadows

Appalachian Mtns

sea breeze effects Florida and Yucatan

Mexican dry valleys

Central American details