Climate Change Is Making Hajj Pilgrimage Hotter, Less Safe: Study

A new study by the Britain-based group World Weather Attribution reveals climate change is reducing the safe weather periods for the annual hajj pilgrimage in western Saudi Arabia. Temperatures in Mecca during May now match summer averages from the 1980s, with extreme heat extending into historically cooler months. The Islamic lunar calendar causes the hajj to occur roughly 11 days earlier each Gregorian year, pushing it closer to summer in the coming decades. This year’s hajj took place in temperatures exceeding 40 degrees Celsius, following the 2024 pilgrimage, where over 1,300 deaths were linked to heat above 50C. Saudi authorities responded by deploying extensive air conditioning, but researchers warn rising temperatures will offset any relief from later timing. Average May temperatures now frequently surpass 32C (90F), up 3.5C since pre-industrial times, according to the study. The hajj, a central Islamic ritual, spans multiple days in and around Mecca, exposing hundreds of thousands to open-air conditions. A 2019 study in *Geophysical Research Letters* projected heat stress could again exceed extreme danger thresholds between 2047–2052 and 2079–2086. While shifting dates may temporarily ease conditions, long-term warming will likely worsen risks for pilgrims. Researchers emphasize climate change is prolonging extreme heat into months previously considered safer. The findings highlight the need for adaptive measures as global temperatures continue to rise, threatening one of the world’s largest religious gatherings.