Highest temperature in Seoul (Incheon) on August 11?

Platform comparison

Market context

On 11 August 2026, the highest temperature recorded at Incheon International Airport Station will fall within one of several defined ranges, measured in degrees Celsius. The market currently prices all outcomes at 0% YES, reflecting either a technical issue with how Polymarket displays the contract on Polygon or genuine uncertainty about which temperature band will settle. Traders holding conditional tokens tied to this market are essentially betting on Seoul's summer heat intensity on a specific date roughly 18 months forward, with settlement determined by Weather Underground's Daily Observations table rather than the more commonly cited Day High & Low summary.

Seoul's August temperatures have historically clustered between 28–32°C as daily highs, though extreme heat events have pushed readings above 35°C in recent years. The summer of 2023 saw multiple days exceed 33°C, whilst 2022 remained comparatively moderate. August 2026 sits at the tail end of what meteorologists track as the East Asian summer monsoon season, when Pacific typhoons and high-pressure systems over the Korean peninsula create volatile conditions. The resolution mechanism's specificity—requiring Daily Observations data rather than headline figures—matters because airport stations sometimes record marginally different peaks than city-centre locations.

Traders monitoring this contract should track June and July 2026 weather patterns, as they typically signal August's trajectory. La Niña or El Niño conditions developing through spring 2026 will influence Pacific jet streams and monsoon intensity. South Korea's meteorological agency publishes seasonal outlooks in May and June; any forecast suggesting above-average heat would likely shift market pricing away from the current 0% floor before settlement approaches.

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 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.

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%.