Traders assign the highest probability to a peak temperature of 39–40°C or above in Jeddah on August 9, reflecting close alignment between recent ensemble forecasts and the city’s coastal climatology. With the Red Sea moderating daytime maxima through persistent humidity and afternoon sea breezes, models show modest spread in boundary-layer heating and wind timing that can shift the daily high by 1–2°C. Ongoing summer high-pressure dominance and low cloud cover favor strong solar insolation, while any earlier-than-normal breeze onset or slight increase in moisture could cap readings near 39°C rather than pushing into the low 40s. Historical August averages of 37–38°C provide the baseline, but short-range model updates over the next 48 hours will refine whether conditions support the upper end of the distribution.