On June 27, 2018, satellites captured this image of rare fair skies over all of the UK and Ireland.
It is a composite image of scenes acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite and by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. While the islands on that day were cloudless, the seas around them were blanketed by lumpy marine stratocumulus clouds. Note, too, the phytoplankton bloom in the North Sea.
Islands tend to have a lot of cloud cover, thanks to the moisture all around them. Landmasses in middle latitudes also tend to be cloudier than other parts of the planet. And the intersections between different atmospheric circulation patterns can lead to a lot of cloud cover.
The United Kingdom and Ireland are among the cloudiest places on Earth. Air masses from the Arctic, southern and northern Europe, the Maritimes, and the Gulf Stream all come crashing together in this region. Yet in late June 2018, England, Ireland, Scotland, and Wales all bathed in a rare day of cloud-free skies.