The short answer
October is one of the best months. Highs are about 28 °C and lows about 15 °C, the first showers may arrive, and the light is long and gold. Our weather notes call it the shoulder-season sweet spot. It is also the start of the Sahara season and a good time to book New Year trips.
In more detail
Our climate table gives October a high of about 28 °C and a low of about 15 °C, with "first showers". Days are warm enough for the pool and cool enough for walking the medina at any hour. Sunset is at about 18:00 by mid-month on GMT, so evenings start a little earlier than they used to.
For the desert, October opens the season. Warm days and cool nights make the camel ride and the camp easy, and the drive over the Tizi n'Tichka is clear of snow. It is also good for the Agafay at sunset and for Atlas walking.
October is planning month for the holidays. New Year camps in the Agafay publish their programmes in autumn and at least one closes bookings on 15 December, and Sahara New Year trips sell out first. If you want the desert at New Year, ask for a quote in October or November.