If you visit Meknes during the Summer months, you will appreciate even more the visit to the Mausoleum. Under its roof temperature is a few degrees lower than outside. If you are not in a hurry, take your time. If there are no't many visitors, you can even sit down and relax for a while -- remember this is a sacred place, though.
Note that the colors used in the walls' decorations represent the four Imperial Cities of Fes, Meknes, Marrakech and Rabat.