Figure 4a: Synthesised changes in June-July WBGT intensity across World Cup host stadiums in the 2026 climate relative to a 0.7°C cooler climate representing 1994, the last time FIFA hosted a World Cup in the United States. Observation-based dataset (ERA-Land) is shown in blue, climate model results in red, and the synthesised estimates in magenta. Coloured bars indicate a 95% confidence interval obtained by bootstrapping.