Persistent high-pressure systems over the Arabian Peninsula combined with warm Red Sea surface temperatures drive Jeddah’s mid-August highs into the upper 30s–low 40s °C, aligning with the market’s tight clustering around 39–41 °C. Historical Saudi meteorological records show typical daily maxima of 38–43 °C during this period, with values near 40 °C most common under mostly sunny skies and light northerly winds. Recent model guidance and station observations place tomorrow’s peak near 39–41 °C, with small differences hinging on exact timing of peak insolation, boundary-layer mixing, and any localized sea-breeze effects that could shave 1 °C or allow an extra degree. The Saudi National Center for Meteorology’s next routine update and official daily maximum reading will resolve the market.