Recent forecasts for Jeddah show model outputs clustered between 37–41°C for August 18, driven by peak summer solar insolation, persistent high pressure, and light northwesterly winds that limit cloud cover while allowing modest Red Sea moderation through sea breezes and humidity. Official guidance leans toward 41°C under clear skies, yet some ensembles project 38°C if onshore flow strengthens or timing of the daily maximum shifts. This tight distribution explains the near-even market split between 39°C and 40°C-or-higher outcomes, as small differences in boundary-layer mixing or local coastal effects can alter the recorded peak by 1–2°C. Updated model runs and official maximum readings expected later today will clarify resolution.