Highest temperature in Seoul on July 23?

Platform comparison

Market context

Seoul’s temperature on 23 July will be judged against the daily high recorded at Incheon International Airport Station, and the market is currently pricing a **27°C** outcome as the frontrunner at **49%**, with **28°C** next at **30%**.[1] That is a notably firm lean towards the low end of the late-July range: July normals in Seoul are around **28°C** for daytime highs, with humid conditions and a meaningful rain chance, so a 27°C settlement sits close to climatology rather than implying a heat spike.[2]

The current **0% YES** crowd-implied probability suggests the contract is being treated as effectively decided against the YES side, but that would only be consistent if the market’s YES definition is tied to a narrower target band than the headline temperature outcome. On a cross-platform read, Polymarket is signalling a relatively concentrated distribution around **27–28°C**, while there is no separate sportsbook line in the provided data to confirm whether betting books agree or diverge. In practical terms, analysts usually anchor these summer Seoul temperature markets to broad seasonal norms unless a synoptic feature pushes the forecast materially above or below average.[2]

The main catalysts are the official daily forecast updates for the Seoul/Incheon area, any shift in cloud cover or rainfall timing, and whether a regional high-pressure ridge builds over Korea in time for the airport station’s afternoon maximum. Because the contract resolves from Wunderground’s recorded high at **Incheon Intl Airport Station**, traders will also watch for local station-level differences from city-centre forecasts, which can be several degrees on windy or coastal days. Late revisions matter most if the final temperature sits near a bracket boundary, since a one-degree move can change which range settles.[1][2]

Sources: 1 · 2

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

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'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.

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.