Highest temperature in Seoul on June 30?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded on 30 June 2026 at Incheon International Airport, measured in degrees Celsius and sourced from Wunderground. Historical data frames the current 0% YES probability as a rational market stance: long-term averages for Seoul in June show daytime maximums typically reaching 26°C, with a range of 19–28°C, and the highest recorded temperature this month so far was 34.0°C on 19 June, yet late June often brings the start of the monsoon season, which suppresses peak heat [1][2][8]. The period from 21–30 June historically sees average highs peak at only 21.8°C, suggesting that extreme temperatures are unlikely as the rainy season intensifies [7].

Traders should monitor the Korea Meteorological Administration’s short-range forecasts for any sudden shifts in humidity or cloud cover, as these directly influence maximum temperatures, and watch for official announcements regarding the onset of the monsoon, which typically runs from late June to mid-July [4]. Recent climate monitors confirm that while early June felt like extended spring, increasing humidity and afternoon showers toward the end of the month are now dominant, making extreme heat improbable [2]. The market resolves on-chain via USDC on Polygon using conditional tokens, meaning price movements will hinge entirely on whether Wunderground data records a temperature exceeding the threshold defined by the contract’s resolution ranges, a dependency that remains unfulfilled given current seasonal trends.

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

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.

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.