Keep in mind that Nepal has diverse terrain with elevations ranging from near sea level (40 meters above sea-level) in the sub-tropical jungles of the South to the highest point on earth (8,848 meters) in the North. Hence there is quite a huge variation in temperature. It may be that the southern parts are at 95 Fahrenheit/35 Celsius and Everest Base Camp around freezing temperature on the same day. Although spring and fall are ideal seasons for trekking, the winter and summer also have their unique advantages.
Spring Treks (end February to mid-May)
Spring is an ideal time to go trekking if you like warmer temperatures, clear skies and bright rhododendrons in bloom. Spring temperatures are around 10 degree Fahrenheit warmer than the Fall (Autumn). Annapurna and Everest regions are very popular at this time. There are also a few exciting festivals such as Holi and the Nepali New Year that fall in the Spring.
If you’re planning a trek that involves crossing a high Himalayan pass, it would be recommended to plan one only after April as snow from the Winter can still have accumulated at the pass. Although people doing the Annapurna Circuit Trek (Thorung La) and the Ultimate Everest (Cho La and Teri La) do successfully complete the trek in March. Do expect late-afternoon showers from late March onwards.
Summer Treks (mid-May to mid-September)
Summer brings in the monsoon and weather can be unpredictable. Flight delays and road blocks can happen so your trekking plans will have to be flexible. However, it is a great time to visit the rain shadow areas of Nepal. Also, the rice planting festival (Ropain) takes place around this time which is exciting to watch and take part in.
Ideal destinations are the rain shadow regions of Upper Mustang , Upper Dolpo and Nar Phu. Bring proper rain gear, carry insect repellent and watch out for leeches.
Fall Treks (End September to Early December)
With clear blue skies and bright sunny days, Fall is historically the best time for trekking in Nepal. While days are clear offering great mountain views, nights are cooler compared to Spring Treks. Fall is also when major festivals take place such as Dashain, Tihar and the Mani Rimdu festival in Tengboche (in the Everest region) so you may want to schedule your dates accordingly in order to experience these beautiful festivals.
During early Fall, some trails may be damaged due to the monsoon landslides. Popular trails may be crowded so if you want quiet time opt for a lesser known trek.
Winter Treks (December to February)
Yes, it is cold. Expect below freezing temperatures at elevations above 10,000ft./3,000 meters on most nights with the occasional snow. However, if you are not averse to being a little cold, this is the best time to trek – skies will still be clear during the day and you will be sharing the trail with only a few other people. Mountain biking, from Muktinath to Beni and the Kathmandu rim, is ideal around this time. Bring all cold weather gear including a down parka.
We have organized many high altitude treks to Everest Base Camp and Annapurna Base Camp and a few to Kanchenjunga Base Camp in the Winter. We offer a $150 per person discount on Winter trips.