**Official forecasts from the Korea Meteorological Administration (KMA) set the stage for today’s market.** For August 12 in the Seoul-Incheon area, KMA projects a minimum of 22°C and a maximum of 32°C under clear skies with negligible precipitation risk, consistent with other models showing daytime highs near 32–33°C. This follows a broader heatwave that peaked earlier in the week, with moderating conditions and possible easterly flow introducing slightly cooler maritime air. **Trader consensus splitting between 31°C (44%) and 32°C (37.5%) reflects the narrow scientific margin around the peak.** Incheon’s coastal location introduces sea-breeze effects that can suppress maximum temperatures by 1–2°C relative to inland Seoul through advection of cooler marine air and enhanced mixing. Diurnal heating under strong August insolation typically drives rapid afternoon rises, but even modest increases in boundary-layer moisture, subtle cloud development, or shifts in wind direction can trim the peak by a degree. Measurement at the official Incheon station (versus urban Seoul sites) further amplifies sensitivity to these local factors. **Historical August averages near 30–31°C provide context, yet current model consensus and real-time observations keep probabilities tightly balanced.** Any late-day sea breeze strengthening or minor radiative cooling could favor 31°C resolution, while sustained clear conditions and peak solar heating support 32°C. The low odds on 33°C or higher underscore the limited upside once the heatwave influence wanes.