Highest temperature in Seoul (Incheon) on August 10?

Platform comparison

Market context

Polymarket is pricing this Seoul/Incheon airport heat contract at **0% YES**, so the market is currently implying that the highest temperature recorded in Weather Underground’s Daily Observations table for Incheon Intl Airport Station will *not* land in the settlement range. On Polymarket, traders buy and sell **USDC-denominated conditional tokens** on Polygon, so the live price reflects the market’s view of the final resolved temperature band rather than the headline forecast alone.

That reading sits against a fairly warm late-summer setup, but not an extreme one. Korean Meteorological Administration guidance for the Seoul-Incheon area points to highs around **33°C to 35°C** on 10 August, while SBS English reported Seoul and Incheon at about **33°C** and described ongoing heat precautions. AccuWeather’s Seoul forecast also showed a high near **34°C**, with cloud cover and a low precipitation chance, which suggests a hot day but does not by itself imply a specific hourly peak at Incheon airport.

For traders, the key catalysts are the actual station observations that Weather Underground publishes through the day, especially the midday-to-afternoon window when the daily maximum usually forms, and any short-lived cooling from cloud or coastal breeze. Because the market settles on the **Daily Observations** table rather than the summary high/low panel, the final print matters more than the forecast narrative; the 12:00 UTC settlement window means late data updates close to midday UTC can still affect how the contract resolves. In practice, the main dependencies are the local temperature trace at Incheon, not the broader Seoul forecast.

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

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.

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.