It is easier to cross the desert from north to south.
-The Conquest of the Sahara, Douglas Porch
Not true. Heading up the Darb you’re always facing a fierce headwind. If you want the wind at your back, you’d have to wait until the Khamāsīn (pl., from Khamsīn, Fifty, meaning, the sporadic south-to-north winds that blow in the fifty days following Coptic Easter Monday, in Egypt celebrated as the pre-Islamic holiday Shamm al-Nasīm, Sniff the Breeze!) blows.