When you visit Morocco, your travels will include nights out in the city, trekking through the mountains, camel tours in the desert and cultural excursions. As you pack for your Morocco holiday, you will need to consider what activities you'd like to do, how your clothing will be perceived from a cultural standpoint and what season you will be traveling.
Summer:
If you travel during the summer months, expect warmer temperatures and trekking paths cleared of snow, but higher elevations will be cool year round. In many countries, it is commonplace to pack shorts and a tank top, but don't do that for a trip to Morocco. Instead, pack lightweight pants and shirts (linen works well) but avoid wearing any revealing clothing. Many Moroccans are Muslim, and exposing too much flesh via short shorts, short skirts, and tank tops is not appreciated, especially during daylight hours.
Women would be wise to dress in at least knee-length pants or skirts until evening. In the evening, the nightlife of Morocco may warrant a looser dress code, though this will depend on where you are going and how cosmopolitan a city is. Also, take care to leave local clothing to the locals. While some Moroccans wear djellabas or hip-length tunics, those who live in the city tend to wear Western-style clothing.
Autumn:
Autumn in Morocco is still fairly warm, though temperatures in the mountains begin to drop to 60 degrees Fahrenheit. During the day, a pair of lightweight pants and shirt may be comfortable, but at night you will probably want a jacket when temperatures reach below 50 degrees. The density of the jacket will depend largely on where you plan to travel in the country.
In the desert, nightly temperatures can be much cooler than in the city. If you decide to trek in the mountains, a heavier coat is a good idea. When choosing your clothing you may want to avoid white. The rainy season has yet to begin, so dust in the desert and cities can kick up with wind. White can be cooler; however, you will notice it gets dirty rather quickly.
Winter:
Winter travel will be confined mostly to cultural and city tours, since most of the trekking excursions are not possible due to snow. In winter months, heavier pants and shirts, or even layered clothing, will be most comfortable. Packing layers will allow you to remove or add clothing as needed. Days in the desert will be warm, but plan accordingly for cool evenings and nights in the winter. It is also important to note that the country's rainy season begins in November. During the rainy season it is best to have full rain gear.
Spring:
Spring is one of the wettest seasons in Morocco. The country's rains continue through the end of March, so pack a rain jacket and shoes that are comfortable when wet. An umbrella may be handy in the city, but they are burdensome in the mountains. You should also expect cooler temperatures in the spring. Depending on where you visit, expect day temperatures between 55 and 79 degrees, and at night temperatures fall between 38 and 57 degrees.