Highest temperature in Seoul on July 31?

Platform comparison

Market context

Polymarket has this contract at **0% YES** today, so the on-chain price on Polygon is effectively saying the market does not expect Seoul’s airport station to print a qualifying high within the specified range, even though the actual settlement is tied to the **Incheon Intl Airport Station** reading on Wunderground rather than a city-centre thermometer. The contract resolves through **USDC-settled conditional tokens**, so the only figure that matters is the day’s highest recorded Celsius temperature at that station before the settlement window closes.

That pricing sits against a July climatology that is warm but not unprecedentedly extreme. Seoul’s July averages cluster around the mid-20s Celsius, while comparable forecasts for late July have shown highs in the low- to mid-30s Celsius, and one weather source notes that July is the warmest and rainiest month, with a recorded July Seoul extreme of 38.4°C in historical data.[1][18][19] WeatherSpark also says 31 July is often among the clearer days of the month, which matters because reduced cloud cover can help afternoon temperatures run hotter than the monthly average.[11]

For a trader, the main catalysts are the same local weather drivers that can move the intraday print: heat advisories, monsoon bursts, cloud cover, and any shift in wind or rainfall timing that suppresses the afternoon high. Recent reporting from SBS says intense heat was continuing across South Korea, with Seoul forecast around 34°C and clear weather persisting without significant rain through next week, which is the kind of setup that can push a station reading higher than model averages.[2] Because the market settles on the airport station’s observed high, not the forecast for Seoul generally, the useful watchlist is the Wunderground daily history page, the timing of the afternoon peak, and whether any late cloud or precipitation limits the final hourly maximum.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul on July 31? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Polymarket Alternative UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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.