**Forecast models and observational data point to a narrow band of overnight lows near 29–31°C for Jeddah on August 22, 2026, reflecting the limited diurnal temperature range typical of the Red Sea coastal climate.** August averages show minimum temperatures around 28–30°C, with recent model runs from sources like the Met Office and timeanddate.com indicating 28–30°C, while AccuWeather’s extended outlook centers on 28.7–31.7°C. High humidity from the adjacent sea and light westerly winds suppress radiative cooling after sunset, keeping the lowest readings clustered tightly around the historical baseline of ~30°C. No significant synoptic changes—such as stronger onshore flow or cloud cover—are expected to alter this pattern before resolution. Traders assign the highest implied probabilities to 29–31°C because ensemble spreads remain small and recent short-range guidance shows minimal day-to-day variability, with any shift hinging on the final model update or localized observations near the airport station.