The 2024 Hajj heat disaster: a glimpse into the future

Extreme heat events in the Middle East have become increasingly frequent and intense due to human-driven climate change. During the Hajj pilgrimage in Mecca, Saudi Arabia, in June 2024, temperatures soared to a record-breaking 51.8°C, resulting in the tragic deaths of at least 1,300 pilgrims and over 2,700 non-fatal injuries on 16 June alone. Considering that the intensity and persistence of this heatwave exceed all recorded analogues in the available historical record, it may be considered statistically unprecedented within the context of the observed climate. Our analysis of future projections, tailored for the region, indicates that in a warmer climate, we can expect such devastating events to become a regular occurrence, potentially happening every year. In the hottest scenarios, the absolute maximum temperatures in Mecca are projected to reach or exceed 57°C. Addressing these challenges through effective climate mitigation and adaptation is essential to building resilience against future extreme heat risks.