Jeddah’s Red Sea coastal location creates high uncertainty for the May 18 maximum, as sea breezes, humidity, and subtle shifts in the subtropical high-pressure ridge can swing the daily peak by 3–5 °C. Recent model runs show a tight cluster around 43–46 °C under mostly clear skies and light northerly flow, yet a stronger thermal low or reduced marine influence could push readings into the upper 40s. Historical mid-May data place typical maxima near 36–38 °C, so the market’s spread across the 44–48 °C brackets reflects traders pricing the low-probability tail risk of an unusually intense heat episode driven by minimal cloud cover and warm advection from the interior. Updated National Meteorological Center guidance and next-day model consensus will be the key catalysts for any sharp repricing.