Weather forecasts consistently indicate that the high temperature in Seattle on April 30 will reach 66-72°F, which clearly falls into the '64°F or higher' range [2, 5, 8]. However, the implied probability in the prediction market for this option is only 54.5%. This divergence is likely due to some traders relying on earlier, cooler weather trends or not having updated forecast information. As the date approaches and forecasts become more certain, the market price should converge with mainstream meteorological predictions.

The title asks for Seoul's highest temperature, but the rules explicitly mandate using data from the Incheon Intl Airport Station. Since Incheon and central Seoul can have temperature differences, and data is rounded to whole degrees Celsius, traders who do not read the rules carefully face a significant risk of misjudgment.

Between April 28 and April 30, 2026, the price for '20°C or higher' surged dramatically from 19.6c to 75.2c, while '16°C' and '17°C' plummeted from 24.5c and 19.6c to near 0c, respectively. This occurred because, as the resolution day arrived, forecast models aligned to show a significant warming trend, predicting highs of 20-22°C for the Seoul/Incheon area, effectively ruling out the lower temperature brackets.

April 28, 2026 - April 30, 2026, the price of the '19°C' option surged from 22.5c to a peak of 53c before slightly dropping to 49.5c, as multiple mainstream meteorological agencies concentrated their forecasts around 19°C, boosting market confidence. April 28, 2026 - April 30, 2026, the price of the '20°C' option steadily declined from 37.5c to 17.25c, rebounding slightly to 18.6c, as the market gradually priced out the likelihood of higher-end temperatures with the target date approaching. April 28, 2026 - April 30, 2026, the price of the '18°C' option climbed steadily from 11.5c to a high of 34c before pulling back to 25.5c. This reflects short-term fluctuations in weather models between 18°C and 19°C, prompting defensive capital to hedge on this option.

There is a noticeable divergence. Some weather forecasts (e.g., Wunderground and AccuWeather) show highs reaching 68°F-69°F (corresponding to 20°C or even 21°C) on April 30, yet the prediction market overwhelmingly favors 19°C, with 20°C carrying an implied probability of less than 20%. This is likely because the market anticipates that the actual recorded temperature at the specific London City Airport (EGLC) station might fall slightly below the broader London area forecast, or investors are accounting for a common overestimation bias in weather models.