Highest temperature in Seoul (Incheon) on August 9?

Platform comparison

Market context

Polymarket is pricing this Seoul/Incheon temperature contract at **0% YES** right now, so the market is effectively saying the listed temperature band is not expected to be hit by the highest reading at Incheon Intl Airport Station before settlement. Because the contract is cash-settled in USDC on Polygon through conditional tokens, the practical question for traders is not the abstract weather outlook but whether the Wunderground **Daily Observations** table prints a qualifying maximum in the relevant Celsius bucket by the resolution deadline.

The recent backdrop argues for keeping an eye on upper-end readings rather than seasonal averages. Reuters reported on 6 August that South Korea’s heatwave was expected to peak over Seoul at **39°C**, close to the city’s all-time high of **39.6°C** from August 2018.[6] Coverage from late July and early August also showed multiple national heat records and Seoul-area highs near **40°C**, including a **39.9°C** reading in Yongsan on 7 August, which underlines how quickly the market can reprice if another hot spell materialises.[17][8]

For a trader, the main catalysts are the KMA short-range forecasts, any renewed heatwave advisories, and whether cloud cover or showers reduce daytime mixing enough to cap the airport station’s peak reading.[4][12] The current forecast for Seoul on 9 August points to showers early and an overcast day, with a high around **92°F/33°C** in one commercial forecast, but the settlement source is not a forecast banner; it is the observed Daily Observations entry at Incheon.[12] That means intraday updates matter more than the headline forecast, especially if late-morning heating or a brief clearing allows the airport station to print above expectations.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Seoul (Incheon) on August 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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

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'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.

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 PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.