Cool, dry days make this the best time to visit Morocco. October is perfect for hiking in the mountains and sunning on the beaches. November-February sees snowfall in the mountains, still perfect for travel if you don't mind lower temperatures; the coast can get windy particularly towards evening, but days are still gloriously sunny.
Spring and autumn see milder temperatures in the mountains and on the coast, but spring showers can be expected. September is when the broiling summer ends and temperatures start to dip again as the country edges into its crisp, dry winter months.
Hot and humid conditions with soaring temperatures see a dwindling of crowds. Many desert activities are still on, but mostly in the early morning and evening, avoiding the peak temperatures of the day. The mountains are relatively cooler, but still a time to avoid if it can be helped. The hot and humid conditions also sees a profusion of insects.