Highest temperature in Seoul (Incheon) on August 12?

Platform comparison

Market context

The market is pricing the likelihood that Seoul's highest temperature on 12 August 2026 will fall within a specific range, with settlement based on Incheon International Airport's recorded observations. The 0% implied probability on the YES option suggests the crowd has already assigned the outcome to alternative temperature bands, leaving no residual conviction that this particular range will be the day's peak.

Seoul's August temperatures cluster reliably between 28–34°C, with extreme heat events pushing toward 36–38°C during particularly intense heatwaves. Historical data from the past decade shows that mid-August highs rarely deviate far from the seasonal mean; the 2018 heatwave saw Incheon reach 37.8°C on 5 August, whilst more typical years settle in the 31–33°C band. The current market structure suggests traders have distributed probabilities across multiple temperature brackets based on climatological precedent rather than flagging any single outcome as implausible.

Traders monitoring this market should track the Korean Meteorological Administration's forecasts as August approaches, particularly any alerts regarding high-pressure systems or tropical air masses that could drive anomalous heat. The resolution hinges on Weather Underground's Daily Observations table from Incheon station specifically—not summary figures—meaning data quality and station-specific recording practices matter. Any significant weather pattern shifts in late July or early August could reshape consensus, though the current distribution suggests the crowd has already priced in a range of plausible outcomes with confidence.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.