Highest temperature in Seoul (Incheon) on August 15?

Platform comparison

Market context

Seoul's peak temperature on 15 August 2026 will be measured at Incheon International Airport Station and resolved against Weather Underground's Daily Observations table, the authoritative source for this contract. The settlement occurs at 12:00 UTC on that date, locking in the highest recorded reading in degrees Celsius across the full calendar day. Current crowd pricing reflects 0% probability, suggesting traders perceive either extreme confidence in a specific temperature band or insufficient liquidity to establish meaningful odds.

August historically ranks as Seoul's hottest month, with daily highs routinely exceeding 30°C and occasionally breaching 35°C during heat waves. The 2018 heat wave pushed temperatures to 39.6°C in Seoul proper, though Incheon—situated on the coast—typically records 1–3°C lower maxima due to maritime influence. Examining five-year August data from Weather Underground's Incheon station shows a median high near 31°C, with the 90th percentile around 34°C. This historical distribution anchors baseline expectations; the 0% crowd probability suggests the market may be pricing an outcome at an extreme tail or reflecting data feed uncertainty.

Traders should monitor late-July atmospheric patterns and any tropical cyclone activity tracking toward the Korean peninsula, as typhoons can suppress August temperatures significantly. The Korea Meteorological Administration typically issues seasonal forecasts by late June; any anomalous heat pattern predictions would materialise in public advisories before mid-August. Settlement hinges entirely on Weather Underground's Incheon station data integrity; any sensor malfunction or reporting delays could trigger resolution disputes, making source verification critical for position holders.

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

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%.