Over 1.5 million international pilgrims have arrived in Saudi Arabia for this year's Hajj, according to a government spokesperson on Wednesday.

Hajj, one of Islam’s Five Pillars, is a mandatory religious duty for Muslims who are financially and physically capable. It involves a series of rituals and worship acts that must be completed at least once in a lifetime.

Hajj begins as pilgrims arrive in Mina for day of Tarwiyah

Ghassan Al-Nuwaimi, a spokesperson for the Hajj Ministry, shared an estimate of foreign attendees but did not disclose the number of domestic pilgrims. Last year, 1,611,310 pilgrims came from outside Saudi Arabia.

On Wednesday, pilgrims began arriving at Arafat, with some walking and carrying their belongings in the heat, where temperatures neared 40°C (104°F). Some helped elderly companions along the way. Many paused to rest or eat before continuing to their camps.

Mount Arafat, a rocky elevation southeast of Mecca, holds deep religious importance. It is referenced in the Quran and is believed to be the site where the Prophet Muhammad delivered his final sermon during his last pilgrimage.

Islamic tradition regards the Day of Arafat as the holiest day of the year, when God is believed to come close to worshippers and forgive their sins.

Pilgrims stay in Arafat from after midnight to after sunset, dedicating the time to prayer and reflection. Once the sun sets on Thursday, they will head to Muzdalifah, a nearby plain, to collect stones for an upcoming ritual.

Smart Hajj: How Saudi Arabia Is innovating crowd management for pilgrims

Despite Saudi Arabia’s investment of billions in safety and crowd management, ensuring the well-being of such large numbers remains a challenge—especially with rising temperatures posing a major concern in recent years.

Earlier this week, Health Minister Fahad bin Abdulrahman Al-Jalajel told The Associated Press that 10,000 trees have been planted to offer more shade, hospitals have increased bed availability, and the number of paramedics has tripled.