Recent forecasts for Jeddah show a model spread of roughly 37–41°C for the August 18 peak under mostly sunny skies, with official guidance pointing toward 41°C amid moderate northwesterly winds while other runs favor 38°C. This uncertainty, set against Jeddah’s typical August climatology of 37–38°C highs influenced by Red Sea humidity and coastal breezes, drives the tight split between the 39°C and 40°C-or-higher outcomes. Key differentiating factors include subtle variations in wind speed that affect mixing and heat buildup, potential for brief cloud cover reducing insolation, and exact timing of the daily maximum, all of which traders weigh against historical extremes and ongoing seasonal warmth across the region.