Highest temperature in Seoul (Incheon) on August 16?

Platform comparison

Market context

On 16 August 2026, Seoul's Incheon International Airport weather station will record a daily maximum temperature in Celsius. The market currently prices all temperature ranges at 0% probability on Polygon, suggesting either extreme illiquidity or a technical settlement issue, as historical August data makes some outcomes inevitable. Resolution hinges on Weather Underground's Daily Observations table rather than the Day High & Low summary—a distinction that matters when automated feeds occasionally diverge from manual station records.

Seoul's August climate presents a narrow band of realistic outcomes. The city experiences peak summer heat during mid-August, with historical records showing daily highs typically between 28–33°C at Incheon. The absolute maximum temperature ever recorded in Seoul during August stands at 39.6°C (August 2018), though such extremes remain rare. Most years see the 16th fall within the 29–32°C range, making the current 0% pricing across all brackets anomalous and potentially exploitable if liquidity emerges.

Traders monitoring this contract should track late-July and early-August weather patterns for 2026, particularly the position of the North Pacific high-pressure system and any tropical systems approaching the Korean peninsula. The Korea Meteorological Administration publishes extended forecasts roughly two weeks ahead, providing early signals of whether August will trend hotter or cooler than the 30-year average. Settlement occurs at 12:00 UTC on 16 August, giving traders a defined window to arbitrage any mispricing that emerges as the date approaches and actual forecasts crystallise.

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

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

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 Polymarket Alternative UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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%.