Highest temperature in Seoul (Incheon) on August 5?

Platform comparison

Market context

The event is the highest temperature recorded at Incheon International Airport Station on 5 August, and the current 0% YES price looks far below the day’s weather setup. Seoul-area forecasts this morning point to extreme heat, with one broadcaster saying the capital could reach 38°C and that severe heat-wave warnings were in force across the metropolitan area[1]. Nearby August climatology also sits in the low-to-mid 30s Celsius for daily highs, with Seoul’s monthly forecasts clustering around 31–33°C and occasional peaks into the high 30s[2][4][11].

That matters because this contract resolves to a single daily maximum, not an average, so short-lived clear-sky heating can be enough even if showers appear later. Historical August framing suggests high-thirties are possible in the Seoul region, with cited seasonal records around 38.2°C and the month described as one of the hottest in Korea[15][18]. Against that backdrop, a 0% implied probability appears materially lower than both the weather outlook and the broader seasonal consensus, unless the airport station stays notably cooler than inland Seoul due to marine influence or cloud/rain timing.

Traders should watch the Korea Meteorological Administration short-range updates, any last-minute rain bands over western Korea, and whether showers arrive before the afternoon peak, since the market settles on the day’s highest reading rather than the midday forecast[6][1]. SBS reported clear heat warnings and persistent daytime heat, but also noted showers in parts of the west, which is the main dependency that could cap the ceiling at Incheon[1]. In cross-platform terms, sportsbook-style weather products generally price the more moderate 30–33°C band, while the prediction-market line is still effectively treating a very hot outcome as impossible[2][4][11].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Seoul (Incheon) on August 5? 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.