Raising their palms skywards, the pilgrims set off on the climb to the summit where they held prayers to atone for their sins in a ritual that is regarded as the high point of the annual hajj. "Really, I am very satisfied," said Lassina Coulibaly, a 47-year-old Malian business employee.
"Fatigue is part of the pilgrimage," added the father of seven. Clutching brightly coloured umbrellas, pilgrims first braved the blazing sun and then heavy downpours that many welcomed as a blessing.
Some burst into tears as they chanted prayers. Thousands of faithful had spent the night under the stars, sleeping on prayer rugs or pieces of cardboard. Trucks were parked at regular intervals on the route leading up to the hill, distributing bottles of water and meals.
Thousands of workers prepared to clear the rubbish that littered the ground. Helicopters criss-crossed overhead, part of the tight security precautions taken by the pilgrimage's Saudi hosts. The Hajj is one of the five pillars of Islam which every Muslim is required to complete at least once in their lifetime if they are healthy enough and have the means to do so.
"I came last year during Ramadan, now I am there for the Hajj," said Indonesian pilgrim Zakir Uddin. "It is an honour, praise be to God," added the 27-year-old cook. Like other male pilgrims, he wears a seamless white garment that covers only one shoulder and emphasises unity regardless of social status or nationality. The women wear loose dresses, most of them white, exposing only their faces and hands. They are designed to help pilgrims enter a state of purity, called Ihram. Uddin, who works in the Saudi city of Jeddah less than 90 kilometres (55 miles) from Makkah, says he is happy to see so many of his compatriots among the pilgrims.
"Indonesians make up the single largest contingent, such is the will of God," he said.
Pilgrims travelling from abroad account for 1.86 million of the 2.48 million taking part in this year's Hajj, according to official figures. After sunset prayers, pilgrims will make their way down Mount Arafat to Muzdalifah, another holy site where they will sleep under the stars to prepare for the final stage of Hajj, a ritual "stoning of the devil". That marks the beginning of Eid al-Adha, the festival of sacrifice, marked on Sunday.
Sheep are traditionally slaughtered for the three-day event, a tribute to the Prophet Abraham's sacrifice of a lamb after God spared Ismael, his son.
Pilgrims then return to the Grand Mosque to perform a final "Tawaf" or walk around the Kaaba.