Peak seasonMid september – Mid December
This is the most popular Trekking season in Annapurna Region . Because of the recent monsoon, everything along the Trekking Area is refreshed, clean and vibrant. Views are usually clear and the weather is generally warm. Night time temperatures drop below freezing still, however, the night skies are often extremely clear. This is the busiest period on the Annapurna Region Trekking
March – May
Towards March the rhododendrons start flowering which brings hill sides alive with flaming colours. Because of the warming weather, this is the second most popular trekking season on the Annapurna region. Most of the snow has dissipated, leaving crystal clear skies. There is often a strange haze that can be seen from the lower altitudes during May. However, this soon passes and cannot be seen from higher up the trail. As the monsoon period builds towards the end of may, the days become hotter and more humid which makes trekking at lower altitude quite uncomfortable.
Mid December – February
This is the coldest period in the Annapurna Region . Depending on your altitude, day time temperatures will be cold and night time temperatures get well below freezing. The trade off is that the trails are much less busy. Thorung La Pass (After Manang) , Annapurna Base camp ( after Himalayas Hotel) are often blocked with snow and may be closed days on end. Unless the snow blocks most trails, tea houses still remain open during this period Some other short trekking route are open Like Ghorepani Poonhill trekking, Panchase trekking. Clouds prevail more frequently, but there clear days are still common.
June – Mid September
This is the monsoon period. Although there are stories of torrential downpours, mudslides and hordes of leeches, this is rarely the case on the Annapurna Circuit, particular the northern section. Whilst the south section of the Annapurna Circuit near Pokhara does get a lot of rain, the northern parts often receive less than 10% due to its location within a rain shadow. The plus side of trekking in the monsoon period is that many of the flora species flower during this period, making the trek exceptionally beautiful