The blizzard struck during China’s eight-day Golden Week holiday, a peak season for local tourism.
October usually provides clear skies and friendly temperatures, making it one of the favoured months to hike in the Mount Everest area.
Hundreds of hikers made their way to the Karma Valley hiking trail, a lesser-known but scenic route to the base of Everest – which also offers a view of the world’s highest peak.
The heavy snowfall began on Friday evening, intensifying over the weekend, catching mountain guides off guard.
One trekker, who had visited the Himalayas more than a dozen times, told the BBC he had “never experienced weather like this”.
Dong Shuchang, 27, said that several people in his group of 20 showed signs of hypothermia.
Chen Geshuang, who was part of Mr Dong’s hiking group, said the snow was about a metre deep when the group started their retreat on Sunday.
“All of us are experienced hikers,” Ms Chen said. “But this blizzard was still extremely difficult to deal with. I was so lucky to get out.”