Seoul July 23 2026: Will the Day Hit 20 °C or Below?

What is happening now

Polymarket’s event market for the highest temperature in Seoul on July 23, 2026, is structured as a series of binary markets predicting specific temperature thresholds. The primary market asks whether the temperature will be 20°C or below, with “No” (higher than 20°C) currently leading at 99.95% probability. Additional markets break down predictions into narrower ranges (21°C, 22°C, etc.), with the highest-volume market for 28°C showing 99.95% “No” probability. All markets share the same resolution source: Wunderground’s historical data for Incheon Intl Airport Station, which measures temperatures in whole degrees Celsius. The market remains open until July 23, 2026, at 12:00 UTC, with no resolution possible until Wunderground publishes the first data point for that date.

How the market is structured

This is a multi-outcome, binary market structure with 11 distinct temperature thresholds (20°C or below, 21°C, 22°C, …, 30°C or higher). Each market is mutually exclusive, meaning only one can resolve to “Yes.” The “No” outcome dominates across all thresholds, with prices ranging from 0.0005 (extreme 20°C or below) to 0.9995 (28°C and above). The 28°C market has the highest liquidity ($29,073), suggesting significant trader focus on mid-range temperatures. The 30°C+ market uniquely has “Yes” at 99.95% probability, reflecting low confidence in extreme heat.

Path to the leading outcome

For the “No” outcome in the 20°C or below market to resolve, the highest temperature recorded at Incheon Intl Airport Station on July 23, 2026, must exceed 20°C. This would require verification through Wunderground’s historical data, which will be finalized after July 23. Similarly, the 28°C market’s “No” outcome would resolve if the temperature stays below 28°C. The 30°C+ market’s “Yes” outcome would require a temperature of 30°C or higher, though its low liquidity suggests minimal trader conviction.

What could change the pricing

Pricing could shift if Wunderground’s historical data reveals unexpected temperature patterns, such as a heatwave pushing temperatures above 28°C. Conversely, cooler-than-expected conditions might strengthen the 20°C or below market. Additionally, discrepancies in data collection or reporting between now and July 23 could alter resolutions. Markets with higher liquidity (e.g., 28°C) are more susceptible to rapid price changes based on new information.

Editorial read

The market reflects strong consensus that Seoul’s July 23 temperature will exceed 20°C, with traders betting on mid-to-high ranges (28°C) as the most likely outcome. The 30°C+ market’s anomalous “Yes” probability highlights uncertainty about extreme heat, though its low liquidity suggests limited participation. With over $76 million in total volume across all markets, this event has attracted significant attention, likely due to Seoul’s reputation for summer heat. However, the reliance on Wunderground’s post-resolution data introduces uncertainty, as historical records could be revised. Traders should monitor weather forecasts and Wunderground’s data updates as the deadline approaches.