Why is it so hard to get a cloud-free satellite image of Scotland? The answer is climatological.
Eighty-four years ago today, on May 2, 1933, Scotland's Inverness Courier reported a sighting of the Loch Ness Monster! No, there aren't any satellite images offering proof of the monster's existence (sorry if we got your hopes up). In fact, it's often difficult for satellites to get a good view of Scotland! For example, we had to go back to March 25, 2017, the day this true-color image of the region was captured by the NOAA/NASA Suomi NPP satellite, to get a (mostly) cloud-free image.
Why? It all has to do with the region's Maritime (or Oceanic) climate. In general, areas with Maritime climates lack a dry season -- their precipitation is spread throughout the year -- have many days of cloudy or overcast skies, and experience frequent storms.The responsibility for the UK's cloud cover lies with both the polar jet stream and the North Atlantic Gulf Stream.
Moving in a west-to-east direction across the middle latitudes (45 to 60 degrees), the polar jet brings low pressure systems, storms, and cold fronts to the area, setting up the basic structure of the region's climate. In conjunction, the North Atlantic Gulf Stream, which originates in the warm waters of the Caribbean and pushes warm, moist air up the eastern seaboard of the United States. When this air hits the coast of North Carolina, it is pushed outward, in a north-northeast direction, toward Europe. When they meet over the ocean off the UK's west coast, they result is the overcast, precipitation-rich conditions for which Scotland and the rest of the UK is well-known.