Health officials urged pilgrims to use umbrellas to protect themselves from the scorching sun. They also said no epidemic diseases were recorded so far.
Saudi Arabia, Islam's birthplace, stakes its credibility on providing services to help pilgrims perform the gruelling rituals as comfortably and smoothly as possible.
While thousands of security personnel have been deployed around holy sites, drones are also being used to monitor traffic.
The Hajj this year is back to its pre-pandemic levels when nearly 2.5 million people gathered in Mecca.
The pandemic forced downsizing of the Hajj for three consecutive years, with only a few thousand residents in the kingdom taking part under strict social distancing measures in 2020.
There were some 60,000 pilgrims in 2021 and the number rose to 1 million last year.
The Hajj began on Monday and is expected to end on Friday.
Wednesday marks the start of the Muslim Eid al-Adha festival in Saudi Arabia and many other countries.
