Highest temperature in Seoul (Incheon) on August 1?

Platform comparison

Market context

South Korea’s heatwave has carried into August, and that matters because Incheon is already starting the day warm rather than reset by a cool overnight low. At 5 a.m., Incheon was 27.0°C in one live report, with Seoul at 27.5°C, and the Korea Meteorological Administration also had Incheon’s minimum at 26.8°C earlier in the morning; nearby Seoul hit a tropical-night minimum of 27.4°C.[4][1] That leaves little margin for a modest daytime peak to clear the lower temperature bands, even before the sun drives the day’s maximum.

The current 0% yes pricing looks anchored to a belief that the airport station will fail to post a very high daytime reading, but the broader pattern argues against treating this as a normal August day. South Korea just logged its hottest-ever temperature of 41.4°C in Yangsan on 31 July, while the KMA said parts of the country were still seeing widespread 30s into the morning.[6][10] Seasonal averages for Seoul and Incheon are much lower, around 29°C for typical August highs, so a market in the top end of the range usually needs either an exceptional heat surge or unusually strong local warming to resolve there.[5][13]

Traders should watch the Korea Meteorological Administration’s short-range forecasts and any heat advisories through the afternoon, because those are the main drivers of whether airport temperatures overshoot expectations.[3][12] The key dependency is simple: if the heatwave persists into the western corridor around Seoul and Incheon, the airport can still move sharply higher after sunrise; if marine influence, cloud, or rainfall builds in, the ceiling is much harder to reach. Reuters said the heatwave is not easing quickly, with above-40°C readings already recorded nationally and KMA warning of continued intensity, so the next forecast updates are the important catalyst rather than any scheduled event.[6]

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

Do I need to KYC for this market?

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