Climate change exposes millions of Hajj pilgrims to deadly heat for increasingly longer parts of the year

A World Weather Attribution study finds that climate change has shifted extreme heat earlier into the year in Saudi Arabia, making May temperatures in Mecca as dangerous as summer temperatures were between 1970 and 1990. The analysis indicates that peak May temperatures are now approximately 2°C hotter and average May temperatures are approximately 3.5°C higher than in a preindustrial climate. This trend increases the risk of heat stroke and exhaustion for millions of pilgrims, with projections suggesting that if global temperatures rise by 3°C, 97% of Hajj pilgrimages would occur during periods of dangerous heat.

• Human-induced climate change has caused May temperatures in Mecca to reach levels previously typical of the peak summer months (June to August). Average daily temperatures in May 2026 reached approximately 31.2°C, which is nearly as high as the June-August average temperatures recorded from 1970 to 1990.
• Peak May temperatures of 40°C, which were historically associated with June, July, and August, are now expected to occur every two to three years. These peak temperatures are approximately 2°C hotter than they would have been in a preindustrial climate.
• Average May temperatures have increased by approximately 3.5°C compared to a preindustrial climate. Mean May temperatures exceeding 32°C—the mean summer temperature from 1970-1990—are now expected to occur in most years.
• Future warming trajectories suggest a severe impact on the pilgrimage; if global temperatures increase by 3°C by the end of the century, approximately 97% of all Hajj pilgrimages are expected to take place during periods of dangerous heat in Mecca.
• While Saudi authorities have implemented heat mitigation measures such as cooling stations and shaded walkways, access is not uniform, and pilgrims without official permits may have limited access to medical support, water, and cooling infrastructure.

APA

Barnes, C., Zachariah, M., Philip, S., & Raju, E. (2026). Climate change exposes millions of Hajj pilgrims to deadly heat for increasingly longer parts of the year. World Weather Attribution. https://www.worldweatherattribution.org/climate-change-exposes-millions-of-hajj-pilgrims-to-deadly-heat-for-increasingly-longer-parts-of-the-year/

Chicago

Barnes, Clair, Mariam Zachariah, Sjoukje Philip, and Emmanuel Raju. Climate change exposes millions of Hajj pilgrims to deadly heat for increasingly longer parts of the year. World Weather Attribution, 2026. https://www.worldweatherattribution.org/climate-change-exposes-millions-of-hajj-pilgrims-to-deadly-heat-for-increasingly-longer-parts-of-the-year/.

Wikipedia

{{cite report |last1=Barnes |first1=Clair |last2=Zachariah |first2=Mariam |last3=Philip |first3=Sjoukje |last4=Raju |first4=Emmanuel |title=Climate change exposes millions of Hajj pilgrims to deadly heat for increasingly longer parts of the year |publisher=World Weather Attribution |date=29 May 2026 |url=https://www.worldweatherattribution.org/climate-change-exposes-millions-of-hajj-pilgrims-to-deadly-heat-for-increasingly-longer-parts-of-the-year/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{barnes2026climate, author = {Barnes, Clair and Zachariah, Mariam and Philip, Sjoukje and Raju, Emmanuel}, title = {{Climate change exposes millions of Hajj pilgrims to deadly heat for increasingly longer parts of the year}}, institution = {World Weather Attribution}, year = {2026}, month = may, url = {https://www.worldweatherattribution.org/climate-change-exposes-millions-of-hajj-pilgrims-to-deadly-heat-for-increasingly-longer-parts-of-the-year/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }