Traders assign near-even implied probabilities across 27–31°C for Jeddah’s October 7 minimum because official forecasts from multiple models show nocturnal cooling limited to that narrow band under persistent high pressure and light northwest winds off the Red Sea. High humidity (60–75%) and dew points near 24–26°C suppress radiative cooling, keeping overnight lows from dropping below the mid-20s while daytime heating reaches the mid-30s. Recent model runs indicate minimal cloud cover and no frontal systems, producing only modest differences in boundary-layer mixing that separate the 28–31°C outcomes. Historical October minima for the city average near 28°C, providing a stable baseline that reinforces the tight clustering around these values ahead of final station readings.