Highest temperature in Seoul on July 7?

Platform comparison

Market context

The underlying real-world event is the peak daytime heat expected at Incheon International Airport on 7 July 2026, where historical data places typical midsummer highs between 27°C and 28°C, rarely dipping below 24°C or exceeding 31°C[2][4]. Despite the crowd-implied probability of 0% for the "YES" outcome on this specific prediction contract, the broader Polymarket market for Seoul’s highest temperature on this date currently favours the 27°C range at 33%, with 28°C as the next closest outcome at 26%, suggesting the underlying event is not impossible but rather mispriced by the narrow binary framing[1].

Historical patterns for Seoul in July show that while the monsoon season (Jangma) brings frequent, heavy rainfall that can temporarily suppress temperatures to around 18°C after a shower, the humidity often pushes the "feels like" temperature above 34°C at midday, and average highs consistently hover in the upper 20s[3][5]. Traders should monitor the Korea Meteorological Administration’s short-range forecasts for the 40% probability of precipitation and the timing of the monsoon’s retreat, as a delay could keep temperatures lower, whereas a rapid clearance could trigger a heat spike toward 30°C[3][7]. Recent travel advisories also highlight the Sinchon Water Gun Festival in late July, which indicates active summer festivities and high humidity levels that persist even after rain, reinforcing the likelihood of elevated temperatures if the monsoon clears before 7 July[3].

The on-chain mechanics of this contract, settled in USDC on the Polygon network via conditional tokens, mean that liquidity is thin for the binary outcome, creating a potential arbitrage opportunity if the market fails to account for the typical 27–28°C range[1]. With the settlement window ending at 12:00 UTC on 7 July 2026, the key catalyst is the hourly weather update from Wunderground for Incheon, which will definitively record the highest temperature for all times on that day, making the binary "YES" outcome contingent on whether the temperature exceeds the specific threshold defined in the contract terms[1]. The current 0% probability appears to stem from a misunderstanding of the contract’s threshold rather than the actual weather forecast, as the data consistently supports highs well above freezing and within the typical summer band[2][4].

Sources: 1 · 2 · 3 · 4 · 5

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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.