Highest temperature in Seoul (Incheon) on August 11?

Platform comparison

Market context

Seoul's summer heat has intensified over the past 48 hours as a Pacific high-pressure system strengthens across East Asia, pushing daytime temperatures into the low-to-mid 30s Celsius across the metropolitan region. The Korea Meteorological Administration issued heat advisories for the Seoul metropolitan area on 9 August, with forecasts suggesting sustained warmth through mid-month. August 11 falls within the peak of this heat episode, positioning Incheon International Airport—the designated observation station—to record elevated daily maxima.

Historical August data from Incheon shows that temperatures exceeding 33°C occur in roughly 60–70% of years during the second week of August, with extremes reaching 35–36°C in particularly intense heat waves. The 0% crowd probability currently assigned suggests either extreme scepticism about the specific temperature threshold being tested or a misalignment between market expectations and seasonal norms. August 2023 saw Incheon record 34.2°C on the 11th; August 2022 peaked at 32.1°C on the same date. These comparables indicate that mid-30s readings are well within plausible range for this calendar date.

Traders should monitor the KMA's official forecasts released daily through 10 August, which will refine expectations for wind patterns and cloud cover that influence afternoon peak temperatures. Any shift in the Pacific high's positioning or unexpected cloud development could moderate the forecast downward. The resolution depends on the Daily Observations table at Weather Underground rather than summary figures, so discrepancies between reporting sources may affect settlement interpretation.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

UK Frequently Asked Questions

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.

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%.