Season

Main season for the trek is considered Sep-Dec + Mar-May. May is already quite hot, Jan starts to be quite cold.

Cold, but clear sky and views: February and early March (nights -20°C or colder)

Late March and April are popular months for trekking, with the weather warmer and the rhododendrons and other flowers in bloom further down the trail. Days are beginning to stretch out to provide lots of daylight for exploring, too, with good visibility in the early mornings. In late April, you may come across mountaineers acclimatising at Base Camp before beginning the ascent to Camps I, II and III on Everest's slopes, and finally the attempt on the summit.

Trekking to Base Camp in early May is still possible, just before the monsoon arrives, and you may share space there with mountaineers already involved in a series of 'rotations', in which they climb ever higher up the mountain between dropping back down to Base Camp to recuperate before, ultimately, attempting the summit. The window of good weather needed for this changes each year, depending on the monsoon in Bengal, but most successful summit attempts occur in late May.

By late May the monsoon has arrived in Nepal and lasts through June, July, August and into early September. During the rainy season, it doesn't necessarily rain all day, but it does rain every day, so trails are muddy and rife with leeches, the mountains are often thick with cloud, and landslides are common and disruptive to travel.

The autumn trekking season kicks off in late September as the monsoon dissipates. Clear skies and fresh air characterise this time of year, with October to early November particularly great for trekking. Temperatures are comfortable, although the weather is colder now than during the spring season (around -10 °C at Base Camp during the day), days are dry and views are perfect. The landscape has been washed clean by the monsoon rains, too, and looks particularly lush and verdant. 

There is an Everest summiting window roughly from 1-20 October, so you may also meet climbing parties at Base Camp. 

Late September and October are also when Nepal's most important festival is held, the 15-day long Dashain celebration, when Durga the Goddess of Victory is celebrated with thousands of animal sacrifices. Nepal Airlines even sacrifices goats on the runway of Kathmandu airport.

Late November and December are also good times to go trekking, but it will be colder, with temperatures dropping well below zero at night. The upside is that the trail to Everest Base Camp will be much less busy as people eager to avoid the cold clear out. Tour prices and flight costs tend to drop a little bit now, too.

Our visit in mid Dec was quite late time to do the Everest basecamp trek, there were chilly freezing nights, but the up side was there were not many tourists there. 

Access

Through Lukla airport (considered on of the most dangerous airports in the Workd due to its shortness). But the pilots are professionals, so it is basically safe. 

Flights to Lukla are canceled in a bad weather. It might be canceled just moments before. 

Permits

You need a permit for the area. 

Permits and flight tickets acquired by namastetrek.com.np (Jangbu Sherpa). 

Equipment

Spikes are necessary during the winter season when Cho La (5420 m) pass gets frozen. 

We managed to buy low quality spikes in Namche Bazaar. They just barely fit my shoes (size 46) and survived a few moments of use.

Map of Area