**Clear, sunny conditions under a strengthening high-pressure system are driving trader consensus toward a 21–22°C peak for Incheon on October 2.** Northwesterly winds of 6–8 m/s and minimal cloud cover support efficient daytime heating, yet the cool maritime air mass keeps the maximum modest. Official guidance from the Korea Meteorological Administration and ensemble model runs cluster around 21.0–21.5°C, with minor spread arising from exact timing of the afternoon peak and slight variations in boundary-layer mixing. The near-even split between 21°C (52%) and 22°C (45.5%) reflects this tight uncertainty range, while odds below 20°C or above 23°C remain negligible given the stable synoptic pattern and absence of frontal activity. Final hourly observations from Incheon International Airport will resolve the market.