The best months for the Annapurna Panorama treks are autumn (mid Sept to mid Dec) as the days during this period are usually sunny and warm with clear views, however the nights are rather cold and can drop to freezing point. The winter months of Dec-Feb are also good time for this trip, despite the weather being rather cold. The trekking routes tend to be crowded during the spring and autumn but winter months usually see less tourist activities in this area.