all the answers sofar are accurate. it you are traveling cheap, there are government buses- CTM plus another new service- that travel basically at night and can take you all over Morocco.
After Marrakech, there are no train south or east or west.. it is hot except for the mountains. But in the souks of the larger cities, you can be relatively cool. Try to get an A/C hotel room.
the desert area is very hot. i know. shall go there for o2 days to get my new residency card.. make sure buses are a/c if you use them. taxis are not a/c as i recall.
Can rent cars with a/c....
good traveling... E. Elena Hall, Co Director Blue Men of Morocco Co. Visit us in Morocco!
http://www.bluemenofmorocco.com