Highest temperature in Seoul (Incheon) on August 4?

Platform comparison

Market context

The event is the highest temperature recorded at Incheon International Airport on 4 August, measured in degrees Celsius and resolved from the daily history page rather than a live intraday feed. With the market’s settlement window ending at 12:00 UTC, a programmatic approach would usually poll the underlying station history near and after that cut-off, then map the final maximum into the relevant temperature band once Wunderground has published the day’s completed record.

The current **0% YES** looks inconsistent with the weather backdrop. Seoul-area forecasts for 4 August are clustered around the upper 20s to high 30s in Celsius, with AccuWeather showing Seoul highs of 87°F to 88°F across 4–6 August and local reporting warning of a serious heatwave, with Seoul expected to reach 38°C and Incheon 37°C on 4 August.[1][2][3][4] That matters because the station at Incheon airport typically tracks the same regional heat pool, and the market should be read against a warm-season distribution where mid-30s Celsius is plausible, not exceptional, on the hottest days.[3][13][18]

A trader watching this mechanically should focus on whether afternoon heating is suppressed by cloud, rain, or marine influence, since even scattered showers do not necessarily cap the day’s maximum until late enough to matter.[2][3] The useful inputs are the KMA short-range outlook, the airport-station history page, and any late updates to heat advisories; if the daily high prints before UTC midday, the final band can often be inferred quickly from the station record and automated into conditional orders or bot logic.[4][8]

Sources: 1 · 2 · 3 · 4 · 5

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

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

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Bot UK 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.