More than 1.5 million Muslims will pray on Mount Arafat in soaring temperatures today (Saturday).
Worshippers from all over the world will climb the rocky, 70-metre (230-feet) hill, about 20 kilometres (12 miles) from Makkah, where Prophet Muhammad (PBUH) gave his last sermon.
The desert summer heat is expected to hit 43 degrees Celsius (109.4 degrees Fahrenheit), creating challenges especially among the elderly during a day of prayer and reciting the Holy Quran.
Saudi authorities have urged pilgrims to drink plenty of water and protect themselves from the sun. Since men are prohibited from wearing hats, many carry umbrellas.
Hajj, one of the world’s biggest religious gatherings, is increasingly affected by climate change, according to a Saudi study that said regional temperatures were rising 0.4°C each decade.
Saudi Arabia will observe Eid-ul-Adha tomorrow (Sunday).