Highest temperature in Seoul (Incheon) on August 16?

Platform comparison

Market context

On 16 August 2026, Seoul's Incheon International Airport will record a daily high temperature, and this market prices the probability that it falls within a specific range. The market currently shows 0% implied probability for the YES outcome, suggesting traders expect the actual temperature to fall outside the specified band. Settlement hinges on Weather Underground's Daily Observations table for Incheon station—not the summary display—creating a technical distinction that occasionally matters when automated systems and manual records diverge.

Seoul's August climate is remarkably consistent. Historical data from the past decade shows daily highs in mid-August clustering between 29–33°C, with extreme outliers rare. The 2023 heatwave pushed temperatures to 33.1°C on 15 August, whilst cooler years have seen highs around 28°C. This narrow seasonal band explains why the crowd has priced the YES outcome at zero; unless the specified range sits at an implausible extreme—either below 25°C or above 35°C—the market would typically carry meaningful probability. The current pricing suggests the range itself may be positioned outside historical norms for that date.

Traders should monitor South Korea's meteorological forecasts from late July onwards, particularly any alerts from the Korea Meteorological Administration regarding heat domes or tropical systems. August 2026 falls within the typical typhoon season for the Korean peninsula, though direct hits on Seoul remain uncommon. Any official heat warnings or unusual atmospheric patterns flagged by regional weather services in the weeks before settlement would shift how traders reassess the likelihood of temperatures deviating from the 29–33°C baseline.

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.

UK Frequently Asked Questions

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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.