Total lunar eclipses are visible from half of the globe, so weather prospects are not such a hot topic as for total solar eclipses where the path of totality occurs along a narrow corridor of the Earth. That being said, it is still worth noting where the total phase of this eclipse of the Moon is visible from and what the average cloud cover is experienced in these countries. The diagram below shows the mean cloud cover across the globe for July. These images are compiled from daily measurements acquired by the Aqua satellite between 2002 and 2015
Northern Africa, Southern Africa and Australia are the most appropriate countries to observe this total lunar eclipse from as the chances of clear skies are very good. These countries also provide fantastic landscapes for this low-lying eclipse of the Moon.
Of course all of this is very speculative and actual local weather forecasts are impossible to predict until the days leading up to the eclipse itself.
Areas with less than favourable weather conditions on average are Southern Asia and far Northern Europe. Southern Asia will be deep in to Monsoon season which will no doubt have the potential to drastically hinder observation of this eclipse from that part of the world. Countries that can be affected include India, Nepal, Bangladesh, Bhutan, Pakistan, and Sri Lanka.