Highest temperature in Seoul (Incheon) on August 10?

Platform comparison

Market context

Seoul’s maximum temperature at Incheon Intl Airport on 10 August is the figure this contract will settle on, and the key market wrinkle is that the source is the **Daily Observations** table on Weather Underground rather than the site’s day-high summary. With the crowd showing **0% YES**, the market is pricing in an outcome that is effectively below the lowest listed band, so any meaningful move would need a sharp reassessment of the forecast or a source-specific reporting issue.

On the comparable-data side, August in Seoul is normally hot: Weather Spark and other climatology sources put average August highs around **30°C**, while Weather Underground’s Seoul history page shows recent daily highs in the high 70s °F, with record highs near the upper 90s °F for the date range shown.[8][9][12][4] That matters because a 0% implied probability is not the same as “impossible”; it usually reflects an extreme tail or a contract that traders think is already misaligned with the source mechanics. By contrast, mainstream weather platforms are forecasting a warm day for Seoul, with AccuWeather’s Seoul page showing a **94°F** high for 10 August and the WMO page showing **25°C to 34°C** for the same day.[6][14][12]

The main catalysts are forecast revisions, not news flow: traders should watch how late-morning model updates and local convective rain risk affect the airport reading, because the airport can diverge from city-centre temperatures on sunny or stormy days. The market also depends on the Weather Underground station feed remaining available and internally consistent through the settlement window, since the contract resolves to the highest observed value in that table rather than any summary display.

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 Kalshi vs Polymarket. 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.

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.

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.

Do I need to KYC for this market?

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