**Forecast models for Jeddah on September 16, 2026, currently converge on a daily maximum near 37–38°C under mostly sunny skies, light-to-moderate westerly or southwesterly winds, and moderate humidity (roughly 40–65%).** This places the market’s leading outcomes (38°C at 28%, 39°C at 24%, 37°C at 23%) in a tight cluster, reflecting genuine short-range uncertainty rather than strong directional bias. Key differentiating factors include small differences in predicted peak timing, sea-breeze strength from the Red Sea, and any late-day cloud development that could shave a degree or two off the high. Recent runs show stable high pressure with negligible precipitation risk and daytime highs on September 14–15 already reaching 37–39°C (99–101°F), setting a baseline consistent with September climatology for the region. Traders are therefore weighting the latest high-resolution model guidance and official Saudi meteorological updates, which can shift the exact maximum by 1–2°C as the event nears. The close spread underscores how modest variations in boundary-layer moisture, wind direction, and insolation timing determine whether the peak lands at 37°C, 38°C, or edges into 39°C.