AP PHOTOS: Hundreds scale Mount Everest in a weather-hit climbing season

KATHMANDU, Nepal — Hundreds of climbers and their Sherpa guides scaled Mount Everest this month in Nepal, struggling against harsh weather to make it to the summit of the world's highest mountain before the climbing season finishes at the end of May.

Though several climbers did manage to reach the summit in mid-May, weather conditions deteriorated for days, forcing a retreat to base camp for many, including Kami Rita Sherpa, who was attempting to break his own record by scaling the peak for a 31st time.

He did manage to scale the 8,849-meter (29,032-foot) peak on May 27, but several climbers were not so lucky.

The route to the summit is equipped with ladders and ropes but these are removed at the end of May, marking an end to the climbing season before the monsoon brings heavy rainfall and bad weather.

According to Nepal's Department of Mountaineering, 468 foreign climbers from 57 countries were given permits to climb Everest by the end of May, along with a roughly equal number of Nepalese mountain guides.

Because of the limited windows of good weather near the summit, large numbers of climbers lined up, attached to the single safety rope, which is known as the ''Everest traffic jam.''

''Overall on Everest, weather is the key and it was not same as the forecast. And secondly, it was crowded because both professionals and beginners were there at the same time," said Pasang Rinji Sherpa, a guide, adding that movement was slow because of some of the novice climbers.

Pasang Rinji has already climbed the peak twice but was forced to retreat this time because he got sick on the mountain.

He said there were many cases of flu and the ''Khumbu cough,'' named after a region on Everest, which affects climbers at high altitudes. Some climbers and guides abandoned or postponed their ascent, he said.

He said that only qualified climbers should be allowed to climb the peak to make the experience safer and easier.

''Right now there are beginners with no experience or knowledge and professionals at the same time, and this is causing the problem,'' he said. ''There should be basic knowledge for the climbers to use gear properly and be safe while climbing Everest.''

Six-time Everest summiteer Jenjen Lama said the weather the biggest challenge this year because it would change without warning.

''The weather was very difficult to predict and the forecast would be great for the following day, but on the day the weather would deteriorate every hour or so,'' he said.

Thursday marked the 72nd anniversary of the conquest of Mount Everest by New Zealander Edmund Hillary and his Sherpa guide Tenzing Norgay.