Highest temperature in Seoul on July 23?

Platform comparison

Market context

Polymarket is pricing this Incheon International Airport Station temperature contract at **0% YES** right now, which is a sharp departure from the spread of outcomes being traded on the venue itself. The market settles against the highest temperature recorded on 23 July 2026 at the airport station, using Wunderground’s daily history page and the Celsius range that contains the day’s peak reading.

That zero bid should be read against the normal July climatology rather than against an abstract “hot day” in Seoul. Published seasonal guides put South Korean July highs around 30°C, while Seoul-specific summer references usually place daytime highs in the mid-to-upper 20s, with 27°C and 28°C commonly sitting near the centre of the distribution for late-July conditions.[1][3] Polymarket’s own menu for this contract shows 27°C as the current front-runner at 50%, with 28°C next at 25%, which underlines how unusually low a 0% print is relative to the live book.[2]

For a trader, the main watchpoints are the forecast updates into the local afternoon, plus any shift in cloud cover, rainfall timing, or winds that could cap the airport’s daytime maximum. The settlement source is fixed, so the on-chain mechanics are straightforward: users trade USDC on Polygon into conditional tokens, and resolution will depend on the Wunderground station record rather than Seoul city averages. That makes airport-specific conditions more important than broad regional expectations, especially on a summer day when short-lived showers can suppress the peak temperature while nearby districts remain warmer.[1][3]

Sources: 1 · 2 · 3

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi UK, which mirrors the Polymarket order book directly.

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

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 UK. 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.

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.

Do I need to KYC for this market?

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