Read the latest updates on the Hajj pilgrimage here.
With wind speeds up to 35 kilometres an hour, dust may affect visibility, especially in open areas and on motorways.
Rain and thunderstorms are also possible, and the meteorology centre (NCM) said thunderclouds may affect the southern Makkah region during the period from Dhu Al Hijjah 9 to 13, which fall on July 8-12.
The NCM says some regions of Saudi Arabia are expected to experience thunderstorms from Wednesday to Saturday.
This year, Hajj falls in July, making heatstroke a significant risk for pilgrims.
Saudi Arabia's Ministry of Health on Thursday allocated 238 hospital beds, distributed across Makkah, Madinah and the holy sites, to care for heatstroke patients.
Heatstroke is responsible for 28 per cent of pilgrim deaths during the Hajj season, the ministry said.
Described as the most serious heat-related illness, it occurs after prolonged exposure to high temperatures. The body can no longer cool itself and internal temperatures can quickly rise above 37ºC.
The ministry is advising pilgrims to remain in their tents or in shaded areas during the hottest parts of the day.
Meanwhile, the NCM said that some regions in the kingdom may experience thunderstorms accompanied by hail, with winds and dust storms. Southern parts of the Eastern Province, as well as the southern parts of the Riyadh region will have moderate rain. Rain is also expected in the regions of Al Baha and Makkah on Friday and Saturday, the weather agency said.