Forecast consensus from multiple meteorological services, including hourly model outputs and agency projections as of August 30, centers on a daytime high of 37–39 °C for Jeddah on August 31, driven by typical late-summer Red Sea coastal conditions: strong solar heating under mostly clear skies, light to moderate northwest winds, and high humidity that elevates heat index values near 45–47 °C. These align with August climatological normals of roughly 38–39 °C maxima and explain the market’s heavy weighting toward 38 °C and 39 °C outcomes. Minor model spread around peak timing and local station measurement introduces the modest probability mass at 40 °C, while the absence of unusual synoptic features or forecast revisions keeps lower or higher extremes at negligible implied odds. Updated model runs and official briefings through the evening of August 30 remain the key near-term catalysts.