Africa Plans

With Morocco looming in the near future I am trying to make my plans a little more solid before the trip takes off on the 6th of July. The plan as of now is as follows:

I catch a bus from Birmingham to London early on the morning of the 6th.

Then I catch a flight to Casablanca, Morocco where i will spend a couple of nights at a hostel in town.

After 2 nights in Casablanca I am off to Marrakesh for an undetermined amount of time and then I have the options of:
The Atlas Mountains
The Sahara Desert
Back to beaches of Morocco

Under all normal circumstances I would go with desert, but given the time of year that could prove to be a very hot mistake. The Atlas mountains seem likely to be the best choice due to the cooler climate and I am guessing beaches are the same just about anywhere.