28 July,Lacedelli, Compagnoni, Abram, Gallotti and Rey depart to establish camp VIII at 7,700 metres.
29 July,Bonatti and Gallotti climb to camp VIII with two oxygen masks, one tent and a supply of provisions. Abram and Rey, who are carrying the frames and oxygen bottles, are unable to keep up with them, Abram returns to camp VII and Rey goes to base camp. Lacedelli and Compagnoni attempt to climb to the site of camp IX, but return to camp VIII exhausted after leaving the equipment at the highest point reached so far. In the evening it is decided that Bonatti and Gallotti will go down to camp VII the next day and get the oxygen bottles, while Compagnoni and Lacedelli set up camp IX 100 metres lower than planned to favour the supply of provisions.
30 July,Lacedelli and Compagnoni climb up to recover the sacks and overcome the wall of ice above camp VIII. After a traverse to the left, they establish camp IX over eight thousand metres high, in a position out of sight compared with the line of the climb. Gallotti and Bonatti descend to camp VII and then climb up again with Abram and the Hunza carriers Mahdi and lsakhan. Isakhan stays in camp VIII while Bonatti, Abram and Mahdi continue the ascent carrying the bottles needed for the last leg to the summit. In the late afternoon Abram gives up and returns to camp VIII. In the evening Bonatti and Mahdi are unable to find Lacedelli and Compagnoni's tent, which is not in the place decided the evening before and so they are forced to spend the night in a makeshift bivouac on a steep slope, without any shelter, at 8,100 metres.
31 July,After a terrible night, Bonatti and Mahdi manage to return to camp VIII; the Hunza's feet and hands are seriously frostbitten. Lacedelli and Compagnoni descend to get the oxygen bottles and then climb to the summit. They reach the top of K2, at 8,611 metres, at 6.00pm. They arrive back at camp VIII at 11.00 pm.
1-3 August,All mountaineers return to base camp.
11-23 August,The return trek to Skardu. Ardito Desio stays in Pakistan to complete the expedition's scientific programme.
3 September,Compagnoni, Rey, Pagani and Fantin return to Rome by air.
10 September,The other mountaineers board ship for Italy.
A weak ridge is situated over Afghanistan. It may at times affect the K2-area during the first days giving only risk of occasional showers. Then it seems to become more unsettled with frequent showers due to lows over Kashmir and Tibet.