January doesn't necessarily mean lots of snow, so it's possible to trek to Everest Base Camp then, but it is chilly. Wrap up warm, though, using lots of layers and enjoy being one of very few people up in the Himalayas.

February and early March are cold, especially at night (around -20°C or colder), but you should get clear skies providing good, uninterrupted views of Everest. In addition, the trail will be less busy and the teahouses quieter, giving a sense of true adventure to a trek to Base Camp. You may also catch the Hindu Holi festival, held in either of these months to celebrate the end of winter; Kathmandu is a messy riot of people pelting each other with paint powder.

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.

Photo credits: [Temp chart: Steve Hicks] [Helpdesk: Olga Danylenko] [Kush Hari Phuyal quote: Steve Hicks] [Everest Day: meg and rahul]

Written by: Joanna Simmons