Astonishing footage has emerged from the roof of the world, as hundreds of climbers queued to scale Mount Everest in a single day.

There were a record 274 successful ascents of the world’s highest mountain on Wednesday as climbers took advantage of favourable weather.

“This is the highest ​number of climbers in a single day so far,” Rishi Ram Bhandari from Expedition Operators Association Nepal told Reuters, referring to the record from the mountain’s Nepalese side.

He said the tally could rise further because some climbers who had got to the top might not yet have informed base camp.

Everest can also be scaled from the northern face in China’s Tibet but that route is closed this year.

Wednesday’s effort was the highest number of climbers on a single day since 223 people reached the top of the mountain on May 22, 2019, from the Nepal side and a further 113 made it from the Chinese side.

Footage being shared online shows long queues of climbers waiting for their moment on top of the peak.

Among them was 18-year-old Melburnian Bianca Adler. She became the youngest Australian to reach the summit of the 8850-metre mountain.

“I feel really good but the weather is really bad,” Adler told her father in a radio call shared on Instagram.

“We just need to take some photos and go because it’s a little bit cold and windy and dark up here.”

Bianca Adler documented her Everest climb on social media. Photos: Instagram

Earlier in the week, veteran mountain guide Kami Rita Sherpa scaled Everest for the 32nd time on Sunday, breaking his own record. On Monday, his closest competitor, Pasang Dawa Sherpa, reached the top for the 30th time.

Also, Lakpa Sherpa – the so-called “Mountain Queehn” – scaled Everest for the 11th time, topping her own record for the highest number of climbs by a female climber.

Americans Dave Hahn and Garrett Madison were also among this week’s climbers. With 15 trips to the summit each, they share the record for non-Sherpa climbers and were hoping to add to their tallies.

Overcrowding has been a growing problem on Everest for years. It was highlighted in 2019 with a photo taken by climber Nirmal Purja showing a long line of climbers huddling on an exposed ridge waiting to reach the summit. At the time, he told CNN that about 320 people were waiting in the queue to the top in an area known as the “death zone.”

Climbers queue to reach the Everest summit in 2019. Photo: Nirmal Purja

This year’s Everest climbing season began late because of risk from a huge serac hanging over the key route to the summit. It kept climbers stuck at base camp until specialised high-altitude workers known as “icefall doctors” could remove the massive block of ice about 10 days ago.

Nepalese tourism official Himal Gautam said he had ‌received preliminary ⁠information that more than 250 people reached the peak on Wednesday.

“We wait for climbers to return, give us photographs and other evidence to prove their ascents and provide them with climbing certificates,” Gautam told Reuters.

“Only then we will be able to confirm the numbers.”

About 490 climbers and an equal number of their Sherpa guides are expected to attempt to scale the 8850-metre peak by the end of May when Everest climbing season ends.

That spiralling number has rekindled concerns about overcrowding on the mountain, especially if poor weather shortens the climbing window.

Nepal has responded to safety concerns in recent years with tighter rules and higher feels for climbers – each climb now costs more than $20,000. But some expedition leaders have defended the numbers.

“If teams carry enough oxygen it is not a big problem,” expedition organiser Lukas Furtenbach of Austria’s Furtenbach Adventures said.

“We have mountains in the Alps like the Zugspitze where we have 4000 persons on top per day. So 274 is actually not a big number, considering this mountain is 10 times bigger.”

Thousands of people have climbed Everest since it was first scaled on May 29, 1953, by New Zealand’s Sir Edmund Hillary and Sherpa guide Tenzing Norgay.

-with AAP