Highest temperature in Seoul (Incheon) on August 4?

Platform comparison

Market context

Seoul’s afternoon heat is the main driver here, but the contract settles on the **highest temperature at Incheon International Airport Station**, so traders need to separate the city forecast from the airport reading. Current market pricing of **0% YES** is starkly lower than the live Polymarket board, where the leading bands are clustered around **29°C to 32°C** at roughly **19% each**, with higher bins still present; that spread suggests the crowd sees a modest but real chance of a low-30s outcome rather than a clean sub-30 finish.[12] KMA-linked reporting for 4 August points to **Incheon around 37°C** and **Seoul up to 38°C**, while AccuWeather’s Seoul monthly outlook also has the day at **87°F/75°F** on the date in question, reinforcing that this is a genuine heatwave setup rather than a routine summer reading.[5][1]

Historically, August in Seoul is often hot, humid and volatile, with average highs around the low 30s and the hottest days frequently landing in the mid-30s Celsius rather than the upper 20s.[6][17] That makes the current 0% print look like an outlier relative to the weather backdrop and to the prediction market’s own ladder of outcome prices, which is concentrated well above the lowest bins.[12] The key comparison is between broad seasonal climatology and a one-day airport maximum: even when a city is forecast near 37–38°C, coastal and airport stations can differ materially depending on sea breeze, cloud cover and timing of peak heating.

The main catalysts are the official short-range forecast updates from the Korea Meteorological Administration and any intraday changes in heat advisory language, wind direction or shower coverage, because those can shift the realised maximum at the airport by several degrees.[4][3][7] Reuters reported South Korea’s record heat wave only days ago, including the country’s highest-ever reading, which underlines how extreme the current regime is and why traders are likely anchoring on the latest KMA guidance rather than seasonal norms.[11] For this contract, the relevant question is not whether Seoul is hot, but whether Incheon’s station reaches the specific Celsius range that matches one of the listed bins before the settlement window closes.[12]

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

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 Best Prediction Markets. 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.

Do I need to KYC for this market?

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