Seoul Hit 23°C Low on July 9, Resolving Polymarket | Lines.com

Seoul recorded a minimum temperature of 23 degrees Celsius on July 9, 2026, confirming the resolution of Polymarket’s lowest-temperature market. The reading, consistent across multiple meteorological services, closed a market that had opened with only a 20% probability on the 23 degrees Celsius outcome. Traders who held that position from the start saw their stake fully vindicated.

The market opened with the 23 degrees Celsius bracket priced at 0.20, meaning traders collectively assigned an 80% probability to a warmer overnight low. The price jumped 25% on July 8 as forecast models tightened, then moved another 7.5% and 14% in two separate sessions on July 9 before resolving at 1.00. Total volume reached $42,453, with $33,409 of that changing hands in the final 24 hours. That late-stage rush tells you traders were chasing confirmation, not leading it.

Seoul’s July 9 Low Confirmed at 23 Degrees Celsius

Seoul’s minimum temperature on July 9 came in at 23 degrees Celsius, placing it at the cooler end of the city’s typical July overnight range. QWeather logged the day’s spread as 27 degrees Celsius high and 23 degrees Celsius low, consistent with the Met Office’s recorded minimum for Seoul in that window. At 23 degrees Celsius (73.4 degrees Fahrenheit), the overnight low sat roughly 2 to 5 degrees below what warmer-bias traders had priced in when the market opened. The measurement resolved the market unambiguously, with no dispute across sources.

The final hours before resolution showed the market sprinting toward certainty. The price at close reached 1.00, the full ceiling. Traders who held positions at the 0.20 open captured the entire move, but most of the volume arrived only after forecast models had already pointed firmly at 23 degrees Celsius. The convergence was fast and clean.

Sponsored Partner

How the Market Priced a Cool Seoul Night

The 23 degrees Celsius outcome carried a 20% implied probability at the start of this market. That was wrong. Seoul’s overnight lows in early July typically range from 23 to 27 degrees Celsius, making 23 degrees a realistic outcome, not a fringe one. The market opened pricing 23 degrees as the least likely scenario among the available brackets, only to watch it resolve as the confirmed result. This is a classic underpriced YES. The final close at 1.00 reflects certainty after the fact, not foresight.

Total volume of $42,453 against $200,651 in liquidity signals a moderately active market with significant depth. High liquidity relative to volume kept prices from moving erratically, but the 51% price jump in the final 24 hours shows traders were not positioned correctly ahead of time. The market priced uncertainty effectively in one sense: it stayed open and liquid. But the market mispriced the probability of Seoul’s actual climatological tendency toward cooler early-July lows.

Market Performance Summary

• Resolution Outcome: 23 degrees Celsius (confirmed)
• Opening Implied Probability: 20%
• Final Price at Close: 100%
• Total Volume: $42,453
• Market Assessment: Underpriced YES

What This Resolution Means for Seoul Weather Markets

Seoul’s July overnight lows sit in a compressed band. A market spanning 11 separate temperature brackets from 18 degrees or below to 28 degrees or higher mathematically fragments probability across many bins, which pushes any single outcome toward seemingly low odds. In that context, the 20% opening price on 23 degrees says less about scientific confidence and more about how probability disperses across many discrete buckets. Here’s what the measurements are telling us: 23 degrees Celsius is a historically normal low for Seoul in early July, and a market that opens at 20% on that outcome is reflecting structural fragmentation, not genuine belief that the temperature would be warmer.

For prediction markets built around narrow meteorological brackets, the data doesn’t care about the politics of probability distribution. Seoul sits at roughly 37 degrees north latitude, and its maritime and continental air mass interactions in July produce overnight lows that cluster tightly. Future markets on Seoul temperature will likely see better calibration if traders anchor to climatological base rates rather than spreading probability evenly across bins. The binary-style bracket structure worked here, but the market mispriced the most climatologically probable outcome.

• Seoul’s recorded July 9 minimum of 23 degrees Celsius is consistent with Korea Meteorological Administration historical averages for early July overnight lows in the Han River basin area.
• The $33,409 in final-day volume indicates traders moved heavily into the 23 degrees Celsius position only once real-time observations or short-range forecast guidance confirmed the outcome.
• Markets structured around temperature brackets benefit from climatological anchoring: traders using historical frequency distributions would have assigned a higher prior to the 22 to 24 degrees Celsius range.
• Seoul temperature markets in future summer windows will serve as a useful calibration test for how well prediction market prices track meteorological base rates in high-certainty short-range forecasts.

LINES RESOLUTION VERDICT

UNDERPRICED YES: CONFIRMED AT 23 DEGREES CELSIUS

Seoul’s July 9 overnight low resolved exactly at 23 degrees Celsius, a climatologically unremarkable outcome that the market dramatically underpriced at open. The data doesn’t care about the politics of how probability gets distributed across eleven brackets.

What the market showed: The 23 degrees Celsius outcome opened at 20% implied probability, surged 51% in the final 24 hours as observational data arrived, and closed at 100%. The market was accurate at resolution but badly underpriced the correct outcome at open, confirming that multi-bracket temperature markets often misprice historically normal readings by dispersing probability too broadly.