Recent forecasts for Jeddah indicate typical late-summer conditions with daytime highs centered near 38–39 °C, aligning with the market’s tight clustering around those outcomes. Coastal Red Sea waters near 31 °C provide moderate cooling through sea breezes and higher humidity, while clear skies and strong solar insolation drive peak heating around midday. Northwest winds and low precipitation keep variability low, though small differences in model runs—such as exact wind speed or boundary-layer mixing—can shift the daily maximum by 1–2 °C. Historical August averages near 37–38 °C offer context, and the narrow probability spread among 38 °C, 39 °C, and 40 °C reflects genuine uncertainty in the final observed reading at the official station.