When the FIFA president announced Qatar would host the FIFA World Cup, the initial plan was to run the tournament in Qatar’s summer months of June and July – the off-season for European football. While planning was underway to use technology to cool stadiums, there were overriding issues of extreme heat that needed to be considered for practice fields and fan comfort. We were tasked with exploring the climatic extremes that could be encountered if the Cup was to be run in the summer.

We worked closely with the design teams for the Cup facilities and FIFA World Cup Supreme Committee, providing regular updates on the modelling of the potential and future climate risks for the country. We accessed local climate data, verifying and validating it and processing the latest CMPI5 climate model data for the region. With data in hand and a clear mandate to assess risk, we developed an analysis for not only extreme heat but also other risk factors, such as sandstorms and extreme winds.

The first discovery was related to the winds and the design factors being considered. The stadiums were designed per FIFA design rules to have natural turf and an open roof. New air conditioning technology was being applied. However, we learned that designers were working with incorrect units for wind speed, which meant extreme wind speed risks were undervalued. The open roof posed a threat if strong winds blew across the open top and caused turbulence, reducing the efficiency of the cooling system.

The second revelation was the relationship between daytime and nighttime temperatures. The plan was for all games to be played at night when temperatures were perceived to be lower and, therefore, safer for teams and fans. We took an innovative approach to heat analysis to consider hourly data and the impact of changes in humidity on player and fan comfort and safety. Our modelling dispelled the perception that nighttime was safer. In the summer, it is not uncommon for local winds to shift from seaward during the day to landward in the evening. With this wind change came an increase in humidity. Therefore, at night, the humidex (a measure of how hot we feel) rose noticeably, heightening the risk of heat stroke to fans, in particular, who needed to travel to and from the stadiums at times in non-air-conditioned spaces.

Identifying potentially serious health issues for visitors from countries without built-up tolerance to a high heat index was a critical factor for shifting the Cup to a winter schedule.